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  • 1. Andrade, Pedro Amarante
    et al.
    Wistbacka, Greta
    Larsson, Hans
    Sodersten, Maria
    Hammarberg, Britta
    Simberg, Susanna
    Svec, Jan G.
    Granqvist, Svante
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine. Karolinska Institutet, Sweden.
    The Flow and Pressure Relationships in Different Tubes Commonly Used for Semi-occluded Vocal Tract Exercises2016In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 30, no 1, p. 36-41Article in journal (Refereed)
    Abstract [en]

    This experimental study investigated the back pressure (Pback) versus flow (U) relationship for 10 different tubes commonly used for semi-occluded vocal tract exercises, that is, eight straws of different lengths and diameters, a resonance tube, and a silicone tube similar to a Lax Vox tube. All tubes were assessed with the free end in air. The resonance tube and silicone tube were further assessed with the free end under water at the depths from 1 to 7 cm in steps of 1 cm. The results showed that relative changes in the diameter of straws affect Pback considerably more compared with the same amount of relative change in length. Additionally, once tubes are submerged into water, Pback needs to overcome the pressure generated by the water depth before flow can start. Under this condition, only a small increase in Pback was observed as the flow was increased. Therefore, the wider tubes submerged into water produced an almost constant Pback determined by the water depth, whereas the thinner straws in air produced relatively large changes to Pback as flow was changed. These differences may be taken advantage of when customizing exercises for different users and diagnoses and optimizing the therapy outcome.

  • 2.
    Askenfelt, Anders
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Music Acoustics.
    Hansen, Kjetil Falkenberg
    KTH, School of Computer Science and Communication (CSC), Media Technology and Interaction Design, MID. KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Music Acoustics.
    Granqvist, Svante
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Music Acoustics.
    Hellmer, Kahl
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Orlarey, Y.
    Fober, D.
    Perifanos, K.
    Tambouratzis, G.
    Makropoulo, E.
    Chryssafidou, E.
    Arnaikos, L.
    Rattasepp, K.
    Dima, G.
    VEMUS, Virtual European Music School or A young person's interactive guide to making music2008In: Proceedings of the 28th ISME World Conference, 2008, p. 218-Conference paper (Refereed)
  • 3.
    Dahl, Sofia
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH.
    Granqvist, Svante
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH.
    Ability to determine continuous drift in auditory sequences: Evidence for bias in listeners' perception of tempo2005In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524Article in journal (Other academic)
  • 4. Geneid, A.
    et al.
    Lindestad, P. -A
    Granqvist, Svante
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Basic science.
    Möller, R.
    Södersten, M.
    Long-term follow-up of patients with spasmodic dysphonia and improved voice despite discontinuation of treatment2017In: Folia Phoniatrica et Logopaedica, ISSN 1021-7762, E-ISSN 1421-9972, Vol. 68, no 3, p. 144-151Article in journal (Refereed)
    Abstract [en]

    Objective: To evaluate voice function in patients with adductor spasmodic dysphonia (AdSD) who discontinued botulinum toxin (BTX) treatment because they felt that their voice had improved sufficiently. Patients and Methods: Twenty-eight patients quit treatment in 2004, of whom 20 fulfilled the inclusion criteria for the study, with 3 subsequently excluded because of return of symptoms, leaving 17 patients (11 males, 6 females) included in this follow-up study. A questionnaire concerning current voice function and the Voice Handicap Index were completed. Audio-perceptual voice assessments were done by 3 listeners. The inter- and intrarater reliabilities were r > 0.80. Results: All patients had a subjectively good stable voice, but with differences in their audio-perceptual voice assessment scores. Based on the pre-/posttreatment auditory scores on the overall degree of AdSD, patients were divided into 2 subgroups showing more and less improvement, with 10 and 7 patients, respectively. The subgroup with more improvement had shorter duration from the onset of symptoms until the start of BTX treatment, and included 7 males compared to only 4 males in the subgroup with less improvement. Conclusion: It seems plausible that the symptoms of spasmodic dysphonia may decrease over time. Early intervention and male gender seem to be important factors for long-term reduction of the voice symptoms of AdSD.

  • 5.
    Gleiser, Julieta E.
    et al.
    KTH, Superseded Departments (pre-2005), Speech, Music and Hearing.
    Friberg, Anders
    KTH, Superseded Departments (pre-2005), Speech, Music and Hearing.
    Granqvist, Svante
    KTH, Superseded Departments (pre-2005), Speech, Music and Hearing.
    A method for extracting vibrato parameters applied to violin performance1998In: TMH-QPSR, Vol. 39, no 4, p. 039-044Article in journal (Other academic)
    Abstract [en]

    A method is presented which semi-automatically extracts the fundamental frequency and displays as continuous signals vibrato rate, vibrato extent and sound level. The method is tested on specially made recordings of violin music with piano accompaniment, using a small microphone mounted directly on the violin. The fundamental frequency was successfully extracted by means of a waveform correlation program. Likewise, vibrato rate and extent were extracted separately for each tone from the fundamental frequency signal after elimination of its DC component. The results seem promising, offering the opportunity of visual examination and measurement of changes in vibrato characteristics during performances of entire pieces of music. 

  • 6.
    Granqvist, Svante
    KTH, Superseded Departments, Speech, Music and Hearing.
    Computer methods for perceptual, acoustic and laryngoscopic voice analysis2000Licentiate thesis, comprehensive summary (Other scientific)
  • 7.
    Granqvist, Svante
    KTH, Superseded Departments, Speech, Music and Hearing.
    Computer methods for voice analysis2003Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    This thesis consists of five articles and a summary. Thethesis deals with methods for measuring properties of thevoice. The methods are all computer-based, but utilisedifferent approaches for measuring different aspects of thevoice.

    Paper I introduces the Visual Sort and Rate (VSR) method forperceptual rating of voice quality. The method is based on theVisual Analogue Scale (VAS), but simultaneously shows allstimuli as icons along the VAS on the computer screen. As thelistener places similar-sounding stimuli close to each otherduring the rating process, comparing stimuli becomeseasier.

    Paper II introduces the correlogram. Fundamental frequencyF0 sometimes cannot be strictly defined, particularly forperturbed voice signals. The method displays multipleconsecutive correlation functions in a grey scale image. Thus,the correlogram avoids selecting a single F0 value. Rather itpresents an unbiased image of periodicity, allowing theinvestigator to select among several candidates, ifappropriate.

    PaperIII introduces a method for detection of phonation tobe utilised in voice accumulators. The method uses twomicrophones attached near the subject’s ears. Phase andamplitude relations of the microphone signals are used to forma phonation detector. The output of the method can be used tomeasure phonation time, speaking time and fundamental frequencyof the subject, as well as sound pressure level of both thesubject’s voicing and the ambient sounds.

    Paper IV introduces a method for Fourier analysis ofhigh-speed laryngoscopic imaging. The data from the consecutiveimages are re-arranged to form time-series that reflect thetime-variation of light intensity in each pixel. Each of thesetime series is then analysed by means of Fouriertransformation, such that a spectrum for each pixel isobtained. Several ways of displaying these spectra aredemonstrated.

    Paper V examines a test set-up for simultaneous recording ofairflow, intra-oral pressure, electro-glottography, audio andhigh-speed imaging. Data are analysed with particular focus onsynchronisation between glottal area and inverse filteredairflow. Several methodological aspects are also examined, suchas the difficulties in synchronising high-speed imaging datawith the other signals.

  • 8.
    Granqvist, Svante
    KTH, Superseded Departments, Speech, Music and Hearing.
    The self-to-other ratio applied as a phonation detector for voice accumulation2003In: Logopedics, Phoniatrics, Vocology, ISSN 1401-5439, E-ISSN 1651-2022, Vol. 28, no 2, p. 71-80Article in journal (Refereed)
    Abstract [en]

    A new method for phonation detection is presented. The method utilises two microphones attached near the subject's ears. Simplified, phonation is assumed to occur when the signals appear mainly in-phase and at equal amplitude. Several signal processing steps are added in order to improve the phonation detection, and finally the original signal is sorted in separate channels corresponding to the phonated and non-phonated instances. The method is tested in a laboratory setting to demonstrate the need for some of the stages of the signal processing and to examine the processing speed. The resulting sound file allows for measurement of phonation time, speaking time and fundamental frequency of the subject and sound pressure level of the subject's voice and the environmental sounds separately. The present implementation gives great freedom for adjustment of analysis parameters, since the microphone signals are recorded on DAT tape and the processing is performed off-line on a PC. In future versions, a voice accumulator based on this principle could be designed in order to shorten analysis time and thus make the method more appropriate for clinical use.

  • 9.
    Granqvist, Svante
    KTH, Superseded Departments, Speech, Music and Hearing.
    The visual sort and rate method for perceptual evaluation in listening tests2003In: Logopedics, Phoniatrics, Vocology, ISSN 1401-5439, E-ISSN 1651-2022, Vol. 28, no 3, p. 109-116Article in journal (Refereed)
    Abstract [en]

    This paper introduces the Visual Sort and Rate (VSR) method which can be utilized for perceptual rating of sound stimuli. The method facilitates comparing similar stimuli, thus making the rank ordering of the stimuli easier. To examine the potential benefits of the method, it was compared with two other methods for perceptual rating of audio stimuli. The first method was a straightforward computer-based implementation of a visual analogue scale (VAS) allowing multiple playbacks and re-play of previously heard stimuli (C-VAS). The second method utilized a VAS where the responses were given on paper (P-VAS). The three methods were compared by using two sets of stimuli. The first set was a synthetically generated series of stimuli mimicking the vowel /a/ with different spectral tilts. In this test, a single parameter was rated. The second set of stimuli was a naturally spoken voice. For this set of stimuli three parameters were rated. Results show that the VSR method gave better reliability of the subjects' ratings in the single-parameter tests: Pearson and Spearman correlation coefficients were significantly higher for the VSR method than for the other methods. For the multi-parameter, intra-subject test, significantly higher Pearson correlation coefficients were found for the VSR method than for the VAS on paper.

  • 10.
    Granqvist, Svante
    et al.
    KTH, Superseded Departments, Speech, Music and Hearing.
    Hammarberg, Britta
    The correlogram: A visual display of periodicity2003In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 114, no 5, p. 2934-2945Article in journal (Refereed)
    Abstract [en]

    Fundamental frequency (F-0) extraction is often used in voice quality analysis'. In pathological voices with a high degree of instability in F-0, it is common for F-0 extraction algorithms to fail. In such cases, the faulty F-0 values might spoil the possibilities for further data analysis. This paper presents the correlogram, a new method of displaying periodicity. The correlogram is based on the waveform-matching techniques often used in F-0 extraction programs, but with no mechanism to select an actual F-0 value. Instead, several candidates for F-0 are shown as dark bands. The result is presented as a 3D plot with time on the x axis, correlation delay inverted to frequency on the y axis, and correlation on the z axis. The z axis is represented in a gray scale as in a spectrogram. Delays corresponding to integer multiples, of the period time will receive high correlation, thus resulting in candidates at F-0, F-0/2, F-0/3, etc. While the correlogram, adds little to F-0 analysis of normal voices, it is useful for analysis of pathological voices since it illustrates the full. complexity of the periodicity in the voice signal. Also, in combination with manual tracing, the correlogram can be used for semimanual F-0 extraction. If so, F-0 extraction can be performed on many voices that cause problems for conventional F-0 extractors. To demonstrate the properties of the method it is applied to synthetic and natural voices, among them six pathological voices, which are characterized by roughness, vocal fry, gratings/scrape, hypofunctional breathiness and voice breaks, or combinations of these.

  • 11.
    Granqvist, Svante
    et al.
    KTH, Superseded Departments, Speech Transmission and Music Acoustics.
    Hertegård, S.
    Larsson, H.
    Sundberg, J.
    Simultaneous analysis of vocal fold vibration and transglottal airflow: Exploring a new experimental setup2003In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 17, no 3, p. 319-330Article in journal (Refereed)
    Abstract [en]

    The purpose of this study was to develop an analysis system for studying the relationship between vocal fold vibration and the associated transglottal airflow. Recordings of airflow, electroglottography (EGG), oral air pressure, and acoustic signals were performed simultaneously with highspeed imaging at a rate of approximately 1900 frames/s. Inverse filtered airflow is compared with the simultaneous glottal area extracted from the highspeed image sequence. The accuracy of the synchronization between the camera images and the foot pedal synchronization pulse was examined, showing that potential synchronization errors increase with time distance to the synchronization pulse. Therefore, analysis was limited to material near the synchronization pulse. Results corroborate previous predictions that air flow lags behind area, but also they reveal that relationships between these two entities may be complex and apparently varying with phonation mode.

  • 12.
    Granqvist, Svante
    et al.
    KTH, Superseded Departments, Speech, Music and Hearing.
    Lindestad, Per-Åke
    A method of applying Fourier analysis to high-speed laryngoscopy2001In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 110, no 6, p. 3193-3197Article in journal (Refereed)
    Abstract [en]

    A new method for analysis of digital high-speed recordings of vocal-fold vibrations is presented. The method is based on the extraction of light-intensity time sequences from consecutive images, which in turn are Fourier transformed. The spectra thus acquired can be displayed in four different modes, each having its own benefits. When applied to the larynx, the method visualizes oscillations in the entire laryngeal area, not merely the glottal region. The method was applied to two laryngoscopic high-speed image sequences. Among these examples, covibrations in the ventricular folds and in the mucosa covering the arytenoid cartilages were found. In some cases the covibrations occurred at other frequencies than those of the glottis.

  • 13.
    Granqvist, Svante
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Basic science. Karolinska Institutet (KI), Sweden.
    Simberg, S.
    Hertegård, S.
    Holmqvist, S.
    Larsson, H.
    Lindestad, P. -Å
    Södersten, M.
    Hammarberg, B.
    Resonance tube phonation in water: High-speed imaging, electroglottographic and oral pressure observations of vocal fold vibrations - A pilot study2015In: Logopedics, Phoniatrics, Vocology, ISSN 1401-5439, E-ISSN 1651-2022, Vol. 40, no 3, p. 113-121Article in journal (Refereed)
    Abstract [en]

    Phonation into glass tubes (resonance tubes), keeping the free end of the tube in water, has been a frequently used voice therapy method in Finland and more recently also in other countries. The purpose of this exploratory study was to investigate what effects tube phonation with and without water has on the larynx. Two participants were included in the study. The methods used were high-speed imaging, electroglottographic observations of vocal fold vibrations, and measurements of oral pressure during tube phonation. Results showed that the fluctuation in the back pressure during tube phonation in water altered the vocal fold vibrations. In the high-speed imaging, effects were found in the open quotient and amplitude variation of the glottal opening. The open quotient increased with increasing water depth (from 2 cm to 6 cm). A modulation effect by the water bubbles on the vocal fold vibrations was seen both in the high-speed glottal area tracings and in the electroglottography signal. A second experiment revealed that the increased average oral pressure was largely determined by the water depth. The increased open quotient can possibly be explained by an increased abduction of the vocal folds and/or a reduced transglottal pressure. The back pressure of the bubbles also modulates glottal vibrations with a possible massage effect on the vocal folds. This effect and the well-defined average pressure increase due to the known water depth are different from those of other methods using a semi-occluded vocal tract.

  • 14.
    Granqvist, Svante
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Sundberg, Johan
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH.
    Lundberg, J. O.
    Weitzberg, E.
    Paranasal sinus ventilation by humming2006In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 119, no 5, p. 2611-2617Article in journal (Refereed)
    Abstract [en]

    The gas nitric oxide (NO) is generated in the human paranasal sinuses and can be measured in nasally exhaled air. During humming, a marked increase in exhaled NO content has been observed. The acoustic phenomenon responsible for this evacuation of NO gas from the sinuses was analyzed. A tube model was constructed with a syringe containing NO gas attached radially. This tube was excited with an air stream modulated by a sine wave. Increased evacuation was observed whenever the syringe was not located at a pressure node of the exciting sine wave. A computer model of the system showed a good matching of observed pressure versus frequency data in the syringe resonator. The results thus suggest that the alternating pressure in the nasal cavity forces the air plug in the ostium of the paranasal sinus resonators to vibrate, thus expelling from the cavity NO gas, which is transported to free air by the exhalatory air stream.

  • 15.
    Granqvist, Svante
    et al.
    KTH, Superseded Departments, Speech Transmission and Music Acoustics.
    Sundberg, Johan
    KTH, Superseded Departments, Speech Transmission and Music Acoustics.
    Wetzberg, J. E.
    Lundberg, J.
    Acoustic modeling of NO gas evacuation from the maxillar sinuses2004Conference paper (Refereed)
  • 16.
    Hagberg, Emilie
    et al.
    Karolinska Univ Hosp, Dept Reconstruct Plast Surg, Stockholm Craniofacial Team, Stockholm, Sweden.
    Flodin, Stina
    Granqvist, Svante
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Basic Science. Karolinska Inst, Dept Clin Sci Intervent & Technol, Div Speech & Language Pathol, Stockholm, Sweden.
    Karsten, Agneta
    Neovius, Erik
    Lohmander, Anette
    The Impact of Maxillary Advancement on Consonant Proficiency in Patients With Cleft Lip and Palate, Lay Listeners' Opinion, and Patients' Satisfaction With Speech2019In: The Cleft Palate-Craniofacial Journal, ISSN 1055-6656, E-ISSN 1545-1569, Vol. 56, no 4, p. 454-461Article in journal (Refereed)
    Abstract [en]

    Objective: This study investigates the impact of maxillary advancement (Le Fort Iosteotomy) on consonant proficiency in patients with cleft lip and palate (CLP) and explores how these patients and lay people perceive their speech 1 year post Le Fort I osteotomy. Design: Retrospective group study before and after treatment. Participants: All patients with CLP who had undergone Le Fort I osteotomy for maxillary retrognathia between 2007 and 2010 at Karolinska University Hospital, Sweden (n = 21). Six patients were excluded due to additional malformations and missing data. Two experienced speech and language pathologists assessed consonant proficiency, and speech accuracy was determined by lay listeners from pre- and postoperative standardized audio recordings. The patients' satisfaction with speech postoperatively was collected from medical records. Main Outcome Measures: Percentage of oral consonants correct and acoustic analysis of /s/, lay listeners' opinion, and patients' satisfaction with speech. Results: One year postoperation, 11 of the 15 patients had improved articulation, especially on the /s/-sound, without speech intervention. The mean percentage of oral consonants correct before treatment (82%) was significantly improved later (95%; P > .01). This assessment was supported by the patients' satisfaction with speech. However, lay listeners' opinion on accuracy was inconsistent. Length of maxillary advancement or change in occlusion did not correlate with change in articulation. Conclusion: Maxillary advancement performed to normalize occlusion and facial profile improved consonant proficiency in patients with CLP 1 year postoperation. Lay listeners' and patients' perceptions of speech need further exploration.

  • 17. Hertegård, S.
    et al.
    Granqvist, Svante
    KTH, Superseded Departments, Speech Transmission and Music Acoustics.
    Lindestad, P. A.
    Botulinum toxin injections for essential voice tremor2000In: Annals of Otology, Rhinology and Laryngology, ISSN 0003-4894, E-ISSN 1943-572X, Vol. 109, no 2, p. 204-209Article in journal (Refereed)
    Abstract [en]

    Fifteen patients, 13 women and 2 men, with a mean age of 72.7 years (56 to 86 years) and a clinical diagnosis of essential voice tremor, were treated with botulinum injections to the thyroarytenoid muscles, and in some cases, to the cricothyroid or thyrohyoid muscles. Evaluations were based on subjective judgments by die patients, and on perceptual and acoustic analysis of voice recordings. Subjective evaluations indicated that the treatment had a beneficial effect in 678 of the patients. Perceptual evaluations showed a significant decrease in voice tremor during connected speech (p < .05). Acoustic analysis showed a nearly significant decrease in the fundamental frequency variations (p = .06) and a significant decrease in fundamental frequency during sustained vowel phonation (p <. 01). The results of perceptual evaluation coincided most closely with the subjective judgments. It was concluded that the treatment was successful in 50% to 65% of the patients, depending on the method of evaluation.

  • 18. La, Filipa M. B.
    et al.
    Wistbacka, Greta
    Andrade, Pedro Amarante
    Granqvist, Svante
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Basic science. Karolinska Institutet (KI), Sweden.
    Real-Time Visual Feedback of Airflow in Voice Training: Aerodynamic Properties of Two Flow Ball Devices2017In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 31, no 3, article id UNSP 390.e1Article in journal (Refereed)
    Abstract [en]

    Objectives. Flow ball devices have been used as teaching tools to provide visual real-time feedback of airflow during singing. This study aims at exploring static back pressure and ball height as function of flow for two devices, marketed as flow ball and floating ball game. Study Design. This is a comparative descriptive study. Methods. A flow-driven vocal tract simulator was used to investigate the aerodynamic properties of these two devices, testing them for four different ball sizes. The flow range investigated was between 0 and 0.5 L/s. Audio, flow, pressure, and ball height were recorded. Results. The flow pressure profiles for both tested devices were similar to those observed in previous studies on narrow tubes. For lifting the ball, both devices had a flow and a pressure threshold. The tested floating ball game required considerably higher back pressure for a given flow as compared with the flow ball. Conclusions. Both tested devices have similar effects on back pressure as straws of 3.7 and 3.0 mm in diameter for the flow ball and the floating ball game, respectively. One might argue that both devices could be used as tools for practicing semi-occluded vocal tract exercises, with the additional benefit of providing real-time visual feedback of airflow during phonation. The flow threshold, combined with the flow feedback, would increase awareness of flow, rather than of pressure, during exercises using a flow ball device.

  • 19. Laukkanen, Anne-Maria
    et al.
    Pulakka, Hannu
    Alku, Paavo
    Vilkman, Erkki
    Hertegård, Stellan
    Lindestad, Per-Ake
    Larsson, Hans
    Granqvist, Svante
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    High-speed registration of phonation-related glottal area variation during artificial lengthening of the vocal tract2007In: Logopedics, Phoniatrics, Vocology, ISSN 1401-5439, E-ISSN 1651-2022, Vol. 32, no 4, p. 157-164Article in journal (Refereed)
    Abstract [en]

    Vocal exercises that increase the vocal tract impedance are widely used in voice training and therapy. The present study applies a versatile methodology to investigate phonation during varying artificial extension of the vocal tract. Two males and one female phonated into a hard-walled plastic tube ( 2 cm), whose physical length was randomly pair-wise changed between 30 cm, 60 cm and 100 cm. High-speed image (1900 f/sec) sequences of the vocal folds were obtained via a rigid endoscope. Acoustic and electroglottographic signals (EGG) were recorded. Oral pressure during shuttering of the tube was used to give an estimate of subglottic pressure (P-sub). The only trend observed was that with the two longer tubes compared to the shortest one, fundamental frequency was lower, open time of the glottis shorter, and P-sub higher. The results may partly reflect increased vocal tract impedance as such and partly the increased vocal effort to compensate for it. In other parameters there were individual differences in tube length-related changes, suggesting complexity of the coupling between supraglottic space and the glottis.

  • 20. Lindestad, P. A.
    et al.
    Södersten, M.
    Merker, B.
    Granqvist, Svante
    KTH, Superseded Departments, Speech Transmission and Music Acoustics.
    Voice source characteristics in mongolian throat singing studied with high-speed imaging technique, acoustic spectra, and inverse filtering2001In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 15, no 1, p. 78-85Article in journal (Refereed)
    Abstract [en]

    Mongolian throat singing can be performed in different modes. In Mongolia, the bass-type is called Kargyraa. The voice source in bass-type throat singing was studied in one male singer. The subject alternated between modal voice and the throat singing mode. Vocal fold vibrations were observed with high-speed photography, using a computerized recording system. The spectral characteristics of the sound signal were analyzed. Kymographic image data were compared to the sound signal and flow inverse filtering data from the same singer were obtained on a separate occasion. It was found that the vocal folds vibrated at the same frequency throughout both modes of singing. During throat singing the ventricular folds vibrated with complete but short closures at half the frequency of the true vocal folds, covering every second vocal fold closure. Kymographic data confirmed the findings. The spectrum contained added subharmonics compared to modal voice. In the inverse filtered signal the amplitude of every second airflow pulse was considerably lowered. The ventricular folds appeared to modulate the sound by reducing the glottal flow of every other vocal fold vibratory cycle.

  • 21.
    McAllister, Anita M.
    et al.
    Linköping University.
    Granqvist, Svante
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Sjölander, Peta
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Sundberg, Johan
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Child Voice and Noise: A Pilot Study of Noise in Day Cares and the Effects on 10 Children's Voice Quality According to Perceptual Evaluation2009In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 23, no 5, p. 587-593Article in journal (Refereed)
    Abstract [en]

    The purpose of this investigation was to study children's exposure to background noise at the ears during a normal day at the day care center and also to relate this to a perceptual evaluation of voice quality. Ten children, from three day care centers, with no history of hearing and speech problems or frequent infections were selected as subjects. A binaural recording technique was used with two microphones placed on both sides of the subject's head, at equal distance from the mouth. A portable digital audio tape (DAT) recorder (Sony TCD-D 100, Stockholm, Sweden) was attached to the subject's waist. Three recordings were made for each child during the day. Each recording was calibrated and started with three repetitions of three sentences containing only sonorants. The recording technique allowed separate analyses of the background noise level and of the sound pressure level (SPL) of each subjects' own voice. Results showed a mean background noise level for the three day care centers at 82.6 dBA Leq, ranging from 81.5 to 83.6 dBA Leq. Day care center no. 2 had the highest mean value and also the highest value at any separate recording session with a mean background noise level of 85.4 dBA Leq during the noontime recordings. Perceptual evaluation showed that the children attending this day care center also received higher values on the following voice characteristics: hoarseness, breathiness, and hyperfunction. Girls increased their loudness level during the day, whereas for boys no such change could be observed.

  • 22. Mecke, Ann-Christine
    et al.
    Sundberg, Johan
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Music Acoustics.
    Granqvist, Svante
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Music Acoustics.
    Echternach, Matthias
    Comparing closed quotient in children singers' voices as measured by high-speed-imaging, electroglottography and inverse filtering2012In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 131, no 1, p. 435-441Article in journal (Refereed)
    Abstract [en]

    The closed quotient, i.e., the ratio between the closed phase and the period, is commonly studied in voice research. However, the term may refer to measures derived from different methods, such as inverse filtering, electroglottography or high-speed digital imaging (HSDI). This investigation compares closed quotient data measured by these three methods in two boy singers. Each singer produced sustained tones on two different pitches and a glissando. Audio, electroglottographic signal (EGG), and HSDI were recorded simultaneously. The audio signal was inverse filtered by means of the DECAP program; the closed phase was defined as the flat minimum portion of the flow glottogram. Glottal area was automatically measured in the high speed images by the built-in camera software, and the closed phase was defined as the flat minimum portion of the area-signal. The EGG-signal was analyzed in four different ways using the MATLAB open quotient interface. The closed quotient data taken from the EGG were found to be considerably higher than those obtained from inverse filtering. Also, substantial differences were found between the closed quotient derived from HSDI and those derived from inverse filtering. The findings illustrate the importance of distinguishing between these quotients.

  • 23. Pulakka, H.
    et al.
    Alku, P.
    Granqvist, Svante
    KTH.
    Hertegård, S.
    Larsson, H.
    Laukkanen, A. -M
    Lindestad, P. -Å
    Vilkman, E.
    Analysis of the voice source in different phonation types: Simultaneous high-speed imaging of the vocal fold vibration and glottal inverse filtering2004In: 8th International Conference on Spoken Language Processing, ICSLP 2004, International Speech Communication Association, 2004, p. 1121-1124Conference paper (Refereed)
    Abstract [en]

    Glottal flow waveforms estimated by inverse filtering acoustic speech pressure signals were compared to glottal area functions obtained by digital high-speed imaging of the vocal fold vibration. Speech data consisted of breathy, normal and pressed phonations produced by two male and one female subjects. The results yield both qualitative and quantitative information about the relationship between the glottal flow and the corresponding area function. It was shown, for example, that a distinct knee in the glottal flow waveform in the opening phase corresponds to the abrupt opening of the vocal folds in normal and pressed phonation. In addition, the obtained quantitative data corroborates known theoretical considerations according to which the shape of the glottal flow is more asymmetric than the corresponding area function.

  • 24. Sramkova, Hana
    et al.
    Granqvist, Svante
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Basic science. Karolinska Inst, Sweden.
    Herbst, Christian T.
    Svec, Jan G.
    The softest sound levels of the human voice in normal subjects2015In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 137, no 1, p. 407-418Article in journal (Refereed)
    Abstract [en]

    Accurate measurement of the softest sound levels of phonation presents technical and methodological challenges. This study aimed at (1) reliably obtaining normative data on sustained softest sound levels for the vowel [a:] at comfortable pitch; (2) comparing the results for different frequency and time weighting methods; and (3) refining the Union of European Phoniatricians' recommendation on allowed background noise levels for scientific and equipment manufacturers' purposes. Eighty healthy untrained participants (40 females, 40 males) were investigated in quiet rooms using a head-mounted microphone and a sound level meter at 30 cm distance. The one-second-equivalent sound levels were more stable and more representative for evaluating the softest sustained phonations than the fast-time-weighted levels. At 30 cm, these levels were in the range of 48-61 dB(C)/41-53 dB(A) for females and 49-64 dB(C)/35-53 dB(A) for males (5% to 95% quantile range). These ranges may serve as reference data in evaluating vocal normality. In order to reach a signal-to-noise ratio of at least 10 dB for more than 95% of the normal population, the background noise should be below 25 dB(A) and 38 dB(C), respectively, for the softest phonation measurements at 30 cm distance. For the A-weighting, this is 15 dB lower than the previously recommended value.

  • 25.
    Sundberg, Johan
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Music Acoustics.
    Scherer, Ronald
    Hess, Markus
    Müller, Frank
    Granqvist, Svante
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH.
    Subglottal Pressure Oscillations Accompanying Phonation2013In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 27, no 4, p. 411-421Article in journal (Refereed)
    Abstract [en]

    Acoustic and aerodynamic properties of the voice source and vocal tract have been extensively analyzed during the last half century. Corresponding investigations of the subglottal system are rare but can be assumed to be relevant to voice production. In the present exploratory study, subglottal pressure was recorded in a male adult subject by means of tracheal puncture. Also recorded were the oral airflow and audio signals. Effects of vowel, phonation type, and vocal register shifts on the subglottal pressure waveform were examined. The moment of maximum flow declination rate was synchronous with the main positive peak of the subglottal pressure waveform. The three lowest subglottal resonance frequencies, determined by inverse filtering and long-term average spectra of the subglottal pressure during speech, were found to be about 500, 1220, and 2000 Hz, irrespective of supraglottal variations and phonation type. However, the subglottal pressure waveform was affected by the supraglottal formants, whereas the radiated vowel spectra did not show clear influence by the subglottal resonances. The fundamental frequency immediately preceding and immediately following a register break in pitch glides did not show systematic relationships with formants or with the lowest subglottal resonance.

  • 26. Svec, Jan G.
    et al.
    Granqvist, Svante
    KTH, School of Technology and Health (STH).
    Guidelines for Selecting Microphones for Human Voice Production Research2010In: American Journal of Speech-Language Pathology, ISSN 1058-0360, E-ISSN 1558-9110, Vol. 19, no 4, p. 356-368Article in journal (Refereed)
    Abstract [en]

    Purpose: This tutorial addresses fundamental characteristics of microphones (frequency response, frequency range, dynamic range, and directionality), which are important for accurate measurements of voice and speech. Method: Technical and voice literature was reviewed and analyzed. The following recommendations on desirable microphone characteristics were formulated: The frequency response of microphones should be flat (i.e., variation of less than 2 dB) within the frequency range between the lowest expected fundamental frequency of voice and the highest spectral component of interest. The equivalent noise level of the microphones is recommended to be at least 15 dB lower than the sound level of the softest phonations. The upper limit of the dynamic range of the microphone should be above the sound level of the loudest phonations. Directional microphones should be placed at the distance that corresponds to their maximally flat frequency response, to avoid the proximity effect; otherwise, they will be unsuitable for spectral and level measurements. Numerical values for these recommendations were derived for the microphone distances of 30 cm and 5 cm. Conclusions: The recommendations, while preliminary and in need of further numerical justification, should provide the basis for better accuracy and repeatability of studies on voice and speech production in the future.

  • 27. Södersten, M.
    et al.
    Granqvist, Svante
    KTH, Superseded Departments (pre-2005), Speech Transmission and Music Acoustics.
    Hammarberg, B.
    Szabo, Annika
    Karolinska Institute, Sweden.
    Vocal behavior and vocal loading factors for preschool teachers at work studied with binaural DAT recordings2002In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 16, no 3, p. 356-371Article in journal (Refereed)
    Abstract [en]

    Preschool teachers are at risk for developing voice problems such as vocal fatigue and vocal nodules. The purpose of this report was to study preschool teachers' voice use during work. Ten healthy female preschool teachers working at daycare centers (DCC) served as subjects. A binaural recording technique was used. Two microphones were placed on both sides of the subject's head, at equal distance from the mouth, and a portable DAT recorder was attached to the subject's waist. Recordings were made of a standard reading passage before work (baseline) and of spontaneous speech during work. The recording technique allowed separate analyses of the level of the background noise, and of the subjects' voice sound pressure level, mean fundamental frequency, and total phonation time. Among the results, mean background noise level for the ten DCCs was 76.1 dBA (range 73.0-78.2), which is more than 20 dB higher than what is recommended where speech communication is important (50-55 dBA). The subjects spoke on an average of 9.1 dB louder (p < 0.0001), and with higher mean fundamental frequency (247 Hz) during work as compared to the baseline (202 Hz) (p < 0.0001). Mean phonation time for the group was 17%, which was considered high. It was concluded that preschool teachers do have a highly vocally demanding profession. Important steps to reduce the vocal loading for this occupation would be to decrease the background noise levels and include pauses so that preschool teachers can rest their voices.

  • 28. Tambouratzis, G.
    et al.
    Perifanos, K.
    Voulgari, I.
    Askenfelt, Anders
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Music Acoustics.
    Granqvist, Svante
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Music Acoustics.
    Hansen, Kjetil Falkenberg
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Music Acoustics.
    Orlarey, Y.
    Fober, D.
    Letz, S.
    VEMUS: An integrated platform to support music tuition tasks2008In: 8TH IEEE INTERNATIONAL CONFERENCE ON ADVANCED LEARNING TECHNOLOGIES, PROCEEDINGS / [ed] Diaz, P; Ignacio, A; Mora, E, IEEE Computer Society, 2008, p. 972-976Conference paper (Refereed)
    Abstract [en]

    In this paper, the VEMUS platform is presented, as a novel approach for music tuition that focuses on beginner and intermediate students, typically aged from 9 to 15 years. This platform is characterized by an open, highly interactive and networked multilingual music tuition framework that covers a selection of popular wind instruments. The VEMUS environment integrates innovative, pedagogically-motivated e- learning components to augment traditional music teaching in three distinct learning settings, namely self-practicing, classroom and distance learning. In the present article, the current stage of development of VEMUS is presented, and the areas where it might be of most use towards supporting the educational activities associated with music tuition are identified.

  • 29.
    Ternström, Sten
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Music Acoustics.
    Granqvist, Svante
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Personal computers in the voice laboratory: Part one-the computing environment2009In: Logopedics, Phoniatrics, Vocology, ISSN 1401-5439, E-ISSN 1651-2022, Vol. 34, no 4, p. 224-227Article in journal (Refereed)
  • 30.
    Ternström, Sten
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Music Acoustics.
    Granqvist, Svante
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Personal computers in the voice laboratory: Part two-audio devices2010In: Logopedics, Phoniatrics, Vocology, ISSN 1401-5439, E-ISSN 1651-2022, Vol. 35, no 2, p. 98-102Article in journal (Refereed)
  • 31. Titze, Ingo R.
    et al.
    Baken, Ronald J.
    Bozeman, Kenneth W.
    Granqvist, Svante
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Basic science.
    Henrich, Nathalie
    Herbst, Christian T.
    Howard, David M.
    Hunter, Eric J.
    Kaelin, Dean
    Kent, Raymond D.
    Kreiman, Jody
    Kob, Malte
    Loefqvist, Anders
    McCoy, Scott
    Miller, Donald G.
    Noe, Hubert
    Scherer, Ronald C.
    Smith, John R.
    Story, Brad H.
    Svec, Jan G.
    Ternström, Sten
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH.
    Wolfe, Joe
    Toward a consensus on symbolic notation of harmonics, resonances, and formants in vocalization2015In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 137, no 5, p. 3005-3007Article in journal (Refereed)
  • 32. Wistbacka, Greta
    et al.
    Andrade, Pedro Amarante
    Simberg, Susanna
    Hammarberg, Britta
    Sodersten, Maria
    Svec, Jan G.
    Granqvist, Svante
    KTH, School of Electrical Engineering and Computer Science (EECS), Speech, Music and Hearing, TMH.
    Resonance Tube Phonation in Water-the Effect of Tube Diameter and Water Depth on Back Pressure and Bubble Characteristics at Different Airflows2018In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 32, no 1, article id UNSP 126.e11Article in journal (Refereed)
    Abstract [en]

    Objectives:. Resonance tube phonation with tube end in water is a voice therapy method in which the patient phonates through a glass tube, keeping the free end of the tube submerged in water, creating bubbles. The purpose of this experimental study was to determine flow-pressure relationship, flow thresholds between bubble types, and bubble frequency as a function of flow and back volume. Methods. A flow-driven vocal tract simulator was used for recording the back pressure produced by resonance tubes with inner diameters of 8 and 9 mm submerged at water depths of 0-7 cm. Visual inspection of bubble types through video recording was also performed. Results. The static back pressure was largely determined by the water depth. The narrower tube provided a slightly higher back pressure for a given flow and depth. The amplitude of the pressure oscillations increased with flow and depth. Depending on flow, the bubbles were emitted from the tube in three distinct types with increasing flow: one by one, pairwise, and in a chaotic manner. The bubble frequency was slightly higher for the narrower tube. An increase in back volume led to a decrease in bubble frequency. Conclusions. This study provides data on the physical properties of resonance tube phonation with the tube end in water. This information will be useful in future research when looking into the possible effects of this type of voice training.

  • 33. Švec, J.G.
    et al.
    Granqvist, Svante
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine. Division of Speech and Language Pathology, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.
    Tutorial and guidelines on measurement of sound pressure level in voice and speech2018In: Journal of Speech, Language and Hearing Research, ISSN 1092-4388, E-ISSN 1558-9102, Vol. 61, no 3, p. 441-461Article in journal (Refereed)
    Abstract [en]

    Purpose: Sound pressure level (SPL) measurement of voice and speech is often considered a trivial matter, but the measured levels are often reported incorrectly or incompletely, making them difficult to compare among various studies. This article aims at explaining the fundamental principles behind these measurements and providing guidelines to improve their accuracy and reproducibility. Method: Basic information is put together from standards, technical, voice and speech literature, and practical experience of the authors and is explained for nontechnical readers. Results: Variation of SPL with distance, sound level meters and their accuracy, frequency and time weightings, and background noise topics are reviewed. Several calibration procedures for SPL measurements are described for stand-mounted and head-mounted microphones. Conclusions: SPL of voice and speech should be reported together with the mouth-to-microphone distance so that the levels can be related to vocal power. Sound level measurement settings (i.e., frequency weighting and time weighting/averaging) should always be specified. Classified sound level meters should be used to assure measurement accuracy. Head-mounted microphones placed at the proximity of the mouth improve signal-to-noise ratio and can be taken advantage of for voice SPL measurements when calibrated. Background noise levels should be reported besides the sound levels of voice and speech. 

1 - 33 of 33
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