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  • 101.
    Sjölander, Peta
    et al.
    KTH, Tidigare Institutioner (före 2005), Tal, musik och hörsel.
    Sundberg, Johan
    KTH, Tidigare Institutioner (före 2005), Tal, musik och hörsel.
    Spectrum effects of subglottal pressure variation in professional baritone singers2004Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 115, nr 3, s. 1270-1273Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The audio signal from five professional baritones was analyzed by means of spectrum analysis. Each subject sang syllables [pae] and [pa] from loudest to softest phonation at fundamental frequencies representing 25%, 50%, and 75% of his total range. Ten subglottal pressures, equidistantly spaced between highest and lowest, were selected for analysis along with the corresponding production of the vowels. The levels of the first formant and singer's formant were measured as a function of subglottal pressure. Averaged across subjects, vowels, and F-0, a 10-dB increase at 600 Hz was accompanied by a 16-dB increase at 3 kHz.

  • 102.
    Smeds, Karolina
    et al.
    ORCA-Europe/Widex.
    Leijon, Arne
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. ORCA-Europe/Widex.
    Wolters, Florian
    ORCA-Europe/Widex.
    Hammarstedt, Anders
    ORCA-Europe/Widex.
    Båsjö, Sara
    ORCA-Europe/Widex.
    Hertzman, Sofia
    ORCA-Europe/Widex.
    Comparison of predictive measures of speech recognition after noise reduction processing2014Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 136, nr 3, s. 1363-1374Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A number of measures were evaluated with regard to their ability to predict the speech-recognition benefit of single-channel noise reduction (NR) processing. Three NR algorithms and a reference condition were used in the evaluation. Twenty listeners with impaired hearing and ten listeners with normal hearing participated in a blinded laboratory study. An adaptive speech test was used. The speech test produces results in terms of signal-to-noise ratios that correspond to equal speech recognition performance (in this case 80% correct) with and without the NR algorithms. This facilitates a direct comparison between predicted and experimentally measured effects of noise reduction algorithms on speech recognition. The experimental results were used to evaluate nine different predictive measures, one in two variants. The best predictions were found with the Coherence Speech Intelligibility Index (CSII) [Kates and Arehart (2005), J. Acoust. Soc. Am. 117(4), 2224-2237]. In general, measures using correlation between the clean speech and the processed noisy speech, as well as other measures that are based on short-time analysis of speech and noise, seemed most promising.

  • 103.
    Song, Xue
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Medicinteknik och hälsosystem, Medicinsk avbildning.
    Loskutova, Ksenia
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Medicinteknik och hälsosystem, Medicinsk avbildning.
    Chen, Hongjian
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Medicinteknik och hälsosystem, Medicinsk avbildning.
    Shen, Guofeng
    Shanghai Jiao Tong University.
    Grishenkov, Dmitry
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Medicinteknik och hälsosystem, Medicinsk avbildning. Karolinska Institutet (KI), CLINTEC – Division of Medical Imaging and Technology.
    Deriving acoustic properties for perfluoropentane droplets with viscoelastic cellulose nanofiber shell via numerical simulations2021Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, s. 1750-1761Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Perfluoropentane droplets with cellulose nanofibers (CNF) shells have demonstrated better stability and easier surface modification as ultrasound contrast agents and drug delivery vehicles. This paper presents a theoretical model assuming a four-phase state “inverse antibubble,” with the core filled with gas perfluoropentane surrounded by liquid perfluoropentane. A continuous, incompressible, and viscoelastic stabilizing layer separates the core from the surrounding water. A parametric study is performed to predict the frequency-dependent attenuation coefficient, the speed of sound, and the resonance frequency of the droplets which have a mean diameter of 2.4760.95 lm. Results reveal that the CNF-stabilized perfluoropentane droplets can be modeled in a Rayleigh-Plesset like equation. We conclude that the shell strongly influences the acoustic behavior of the droplets and the resonance frequency largely depends on the initial gas cavity radius. More specifically, the peak attenuation coefficient and peak-to-peak speed of sound decrease with increasing shear modulus, shear viscosity, and shell thickness, while they increase with increasing gas cavity radius and concentration. The resonance frequency increases as shear modulus and shell thickness increase, while it decreases as shear viscosity and gas cavity radius increase. It is worth mentioning that droplet concentration has no effect on the resonance frequency.

  • 104.
    Song, Xue
    et al.
    Shanghai Jiao Tong Univ, Sch Biomed Engn, Shanghai 200030, Peoples R China..
    Shen, Guofeng
    Shanghai Jiao Tong Univ, Sch Biomed Engn, Shanghai 200030, Peoples R China..
    Grishenkov, Dmitry
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Medicinteknik och hälsosystem, Medicinsk avbildning.
    A comparative study on detection of polymer-shelled microbubbles by different excitation pulses2023Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 154, nr 1, s. 482-493Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Contrast agents are widely used in ultrasound imaging. Many imaging techniques have been developed to improve the contrast between tissue and the agents, based on the nonlinear response of microbubbles. In this study, heterodyne excitation was introduced and was compared with traditional sinusoidal signal and chirp excitation for visualizing polymer-shelled microbubbles and degassed water in a tissue-mimicking phantom. Pulse inversion technique was implemented under plane wave (PW) and focused imaging mode. Image enhancement was evaluated by contrast-to-tissue ratio (CTR) at different transmitting peak negative pressures (PNPs). Experimental results showed that heterodyne excitation had a better suppression effect on tissue signals in PW imaging. The CTR reached an approximation of 17 dB at a low peak negative pressure, which was much higher compared to other excitations. In focused wave imaging, a saturation threshold of CTR was observed for the sinusoidal wave burst and chirp excitation at high PNPs. Heterodyne excitation showed considerable contrast-to-noise ratio under both imaging modes. The response of a polymer-shelled microbubble under heterodyne excitation was simulated. Simulations suggest that in future work, specific filters are required to extract the nonlinear components, such as at the two-peak frequencies around fundamental frequency, to achieve a better image enhancement effect.

  • 105. Sramkova, Hana
    et al.
    Granqvist, Svante
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Grundläggande naturvetenskap. Karolinska Inst, Sweden.
    Herbst, Christian T.
    Svec, Jan G.
    The softest sound levels of the human voice in normal subjects2015Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 137, nr 1, s. 407-418Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 106.
    Strömbergsson, Sofia
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH. Karolinska Institutet (KI), Huddinge.
    Salvi, Giampiero
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH.
    House, David
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH.
    Acoustic and perceptual evaluation of category goodness of /t/ and /k/ in typical and misarticulated children's speech2015Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 137, nr 6, s. 3422-3435Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This investigation explores perceptual and acoustic characteristics of children's successful and unsuccessful productions of /t/ and /k/, with a specific aim of exploring perceptual sensitivity to phonetic detail, and the extent to which this sensitivity is reflected in the acoustic domain. Recordings were collected from 4- to 8-year-old children with a speech sound disorder (SSD) who misarticulated one of the target plosives, and compared to productions recorded from peers with typical speech development (TD). Perceptual responses were registered with regards to a visual-analog scale, ranging from "clear [t]" to "clear [k]." Statistical models of prototypical productions were built, based on spectral moments and discrete cosine transform features, and used in the scoring of SSD productions. In the perceptual evaluation, " clear substitutions" were rated as less prototypical than correct productions. Moreover, target-appropriate productions of /t/ and /k/ produced by children with SSD were rated as less prototypical than those produced by TD peers. The acoustical modeling could to a large extent discriminate between the gross categories /t/ and /k/, and scored the SSD utterances on a continuous scale that was largely consistent with the category of production. However, none of the methods exhibited the same sensitivity to phonetic detail as the human listeners.

  • 107. Sun, F.
    et al.
    Li, S.
    He, Sailing
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion.
    Translational illusion of acoustic sources by transformation acoustics2017Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 142, nr 3, s. 1213-1218Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An acoustic illusion of creating a translated acoustic source is designed by utilizing transformation acoustics. An acoustic source shifter (ASS) composed of layered acoustic metamaterials is designed to achieve such an illusion. A practical example where the ASS is made with naturally available materials is also given. Numerical simulations verify the performance of the proposed device. The designed ASS may have some applications in, e.g., anti-sonar detection.

  • 108.
    Sundberg, Johan
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH.
    Fahlstedt, Ellinor
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH.
    Morell, A.
    Effects on the glottal voice source of vocal loudness variation in untrained female and male voices2005Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 117, nr 2, s. 879-885Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Subglottal pressure is one of the main voice control factors, controlling vocal loudness. In this investigation the effects of subglottal pressure variation on the voice source in untrained female and male voices phonating at a low, a middle, and a high fundamental frequency are analyzed. The subjects produced a series of /pae/ syllables at varied degrees of vocal loudness, attempting to keep pitch constant. Subglottal pressure was estimated from the oral pressure during the /p/ occlusion. Ten subglottal pressure values, approximately equidistantly spaced within the pressure range used, were identified, and the voice source of the vowels following these pressure values was analyzed by inverse filtering the airflow signal as captured by a Rothenberg mask. The maximum flow declination rate (MFDR) was found to increase linearly with subglottal pressure, but a given subglottal pressure produced lower values for female than for male voices. The closed quotient increased quickly with subglottal pressure at low pressures and slowly at high pressures, such that the relationship can be approximated by a power function. For a given subglottal pressure value, female voices reached lower values of closed quotient than male voices.

  • 109.
    Sundberg, Johan
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Tal, musik och hörsel, TMH. Univ Coll Mus Educ Stockholm, Stockholm, Sweden..
    La, Filipa
    Natl Distance Educ Univ UNED, Fac Educ, Dept Didact Sch Org & Special Didact, Madrid 28040, Spain..
    Granqvist, Svante
    Karolinska Inst, Dept Clin Sci Intervent & Technol, Div Speech & Language Pathol, Stockholm, Sweden..
    Fundamental frequency disturbances in female and male singers' pitch glides through long tube with varied resistancesa2023Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 154, nr 2, s. 801-807Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Source-filter interaction can disturb vocal fold vibration frequency. Resonance frequency/bandwidth ratios (Q-values) may affect such interaction. Occurrences of fundamental frequency (f(o)) disturbances were measured in ascending pitch glides produced by four female and five male singers phonating into a 70 cm long tube. Pitch glides were produced with varied resonance Q-values of the vocal tract + tube compound (VT + tube): (i) tube end open, (ii) tube end open with nasalization, and (iii) with a piece of cotton wool in the tube end (conditions Op, Ns, and Ct, respectively). Disturbances of f(o) were identified by calculating the derivative of the low-pass filtered f(o) curve. Resonance frequencies of the compound VT+tube system were determined from ringings and glottal aspiration noise observed in narrowband spectrograms. Disturbances of f(o) tended to occur when a partial was close to a resonance of the compound VT+tube system. The number of such disturbances was significantly lower when the resonance Q-values were reduced (conditions Ns and Ct), particularly for the males. In some participants, resonance Q-values seemed less influential, suggesting little effect of source-filter interaction. The study sheds light on factors affecting source-filter interaction and f(o) control and is, therefore, relevant to voice pedagogy and theory of voice production.

  • 110.
    Sundberg, Johan
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH.
    Nordenberg, Maria
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH.
    Effects of vocal loudness variation on spectrum balance as reflected by the alpha measure of long-term-average spectra of speech2006Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 120, nr 1, s. 453-457Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The overall slope of long-term-average spectrum (LTAS) decreases if vocal loudness increases. Therefore, changes of vocal loudness also affects the a measure, defined as the ratio of spectrum intensity above and below 1000 Hz. The effect on a of loudness variation was analyzed in 15 male and 16 female voices reading a text at different degrees of vocal loudness. The mean range of equivalent sound level (Le) amounted to about 28 dB and the mean range of a to 19.0 and 11.7 dB for the female and male subjects. The L-eq vs. alpha relationship could be approximated with a quadratic function, or by a linear equation, if softest phonation was excluded. Using such equations a was computed for all values of L-eq observed for each subject and compared with observed values. The maximum and the mean absolute errors were 2.4 dB and between 0.1 and 0.6 dB. When softest phonation was disregarded and linear equations were used, the maximum error was less than 2 dB and the mean absolute errors were between 0.2 and 0.7 dB. The strong correlation between L-eq and a indicates that for a voice L-eq can be used for predicting alpha.

  • 111.
    Sundberg, Johan
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Tal, musik och hörsel, TMH.
    Salomão, Gláucia Laís
    Stockholm University Brain Imaging Centre (SUBIC), Department of Linguistics, Stockholm University, Stockholm, Sweden.
    Scherer, Klaus R.
    Department of Psychology, University of Geneva, Geneva, Switzerland.
    Emotional expressivity in singing: Assessing physiological and acoustic indicators of two opera singers' voice characteristics2024Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 155, nr 1, s. 18-28Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In an earlier study, we analyzed how audio signals obtained from three professional opera singers varied when they sang one octave wide eight-tone scales in ten different emotional colors. The results showed systematic variations in voice source and long-term-average spectrum (LTAS) parameters associated with major emotion “families”. For two of the singers, subglottal pressure (PSub) also was recorded, thus allowing analysis of an additional main physiological voice control parameter, glottal resistance (defined as the ratio between PSub and glottal flow), and related to glottal adduction. In the present study, we analyze voice source and LTAS parameters derived from the audio signal and their correlation with Psub and glottal resistance. The measured parameters showed a systematic relationship with the four emotion families observed in our previous study. They also varied systematically with values of the ten emotions along the valence, power, and arousal dimensions; valence showed a significant correlation with the ratio between acoustic voice source energy and subglottal pressure, while Power varied significantly with sound level and two measures related to the spectral dominance of the lowest spectrum partial. the fundamental.

  • 112. Svec, Jan G.
    et al.
    Sundberg, Johan
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH.
    Hertegård, Stellan
    Three registers in an untrained female singer analyzed by videokymography, strobolaryngoscopy and sound spectrography2008Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 123, nr 1, s. 347-353Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    There has been a lack of objective data on the singing voice registers, particularly on the so called "whistle" register, occurring in the top part of the female pitch range, which is accessible only to some singers. This study offers unique strobolaryngoscopic and high-speed (7812.5 images/s) videokymographic data on the vocal fold behavior of an untrained female singer capable of producing three distinct voice qualities, i.e., the chest, head and whistle registers. The sound was documented spectrographically. The transition from chest to head register, accompanied by pitch jumps, occurred around tones 134-C#5 (500-550 Hz) and was found to be associated with a slight decrease in arytenoids adduction, resulting in decrease of the closed quotient. The register shifts from head to whistle, also accompanied by pitch jumps, occurred around tones E5-B5 (670-1000 Hz) without any noticeable changes in arytenoids adduction. Some evidence was found for the vocal. tract influence on this transition. The mechanism of the vocal fold vibration in whistle register was found principally similar to that at lower registers: vibrations along the whole glottal length and vertical phase differences (indicated by sharp lateral peaks in videokymography) were seen on the vocal folds up to the highest tone G6 (1590 Hz).

  • 113. Tamadapu, Ganesh
    et al.
    Grishenkov, Dmitry
    KTH, Skolan för teknik och hälsa (STH), Medicinsk teknik, Medicinsk bildteknik.
    Eriksson, Anders
    Modeling and parametric investigation of thick encapsulated microbubble's nonspherical oscillations2016Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 140, nr 5, s. 3884-3895Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Numerous studies have been carried out in the past few decades to investigate the radial oscillations of encapsulated microbubbles (MBs). Nonspherical oscillations also have gained attention, being unavoidable in actual applications of these bubbles. The present paper is intended to describe the nature of resonance trends of such spherical and nonspherical modes of a thick encapsulated MB filled with air and suspended in water. The shell material is assumed to be linear viscoelastic and quasi-incompressible. The considered isotropic and spherically isotropic material parametric range is limited to thick polymer shelled MBs. For the case of an isotropic material, shell viscosity has a major influence on the fundamental modes with meridional wave number n = 0, 4, especially for thicker bubbles, unlike for the case of the spherically isotropic material case considered, where the viscosity has very little influence. For most of the parametric range, n = 2, 3 modes are underdamped and their frequency is found to be lower than the n = 0, 4 modes, for both material cases. An interesting case is found for a spherically isotropic quasiincompressible material case, where the first few nonspherical mode resonances are very close to radial mode resonance frequency.

  • 114.
    Temiz, Muttalip Askin
    et al.
    Eindhoven University of Technology, Department of Mechanical Engineering, Dynamics and Control, The Netherlands.
    Arteaga, Ines Lopez
    Eindhoven University of Technology, Department of Mechanical Engineering, Dynamics and Control, The Netherlands.
    Efraimsson, Gunilla
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellence Center for ECO2 Vehicle design.
    Åbom, Mats
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Hirschberg, Avraham
    Eindhoven University of Technology, Department of Applied Physics, Gas Dynamics and Aero-Acoustics, The Netherlands.
    The influence of edge geometry on end-correction coefficients in micro perforated plates2015Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 138, nr 6, s. 3668-3677Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Global expressions are proposed for end-correction coefficients in micro perforated plates (MPPs) using non-dimensional parameters. MPPs are sound absorbers with small perforation diameters such that the Stokes boundary layers fill up almost the entire perforation. Sound absorption does not only occur within the perforation, but also takes place just outside of it. The latter contribution plus the outside inertia effect on the transfer impedance of the MPP are referred to as end-corrections. In order to determine them, an analytical solution employing the very thin Stokes layer assumption has been derived. However, this assumption requires empirical coefficients in the end-corrections for accurate results. To explore the effects of various parameters a numerical model is used. This model is verified with open-end reflection coefficient measurements. The most prominent result from this study is that compared to plate thickness, the ratio of perforation diameter to Stokes layer thickness (Shear number) and edge geometry affect the end-correction coefficients more significantly. The effect of plate thickness can be neglected for practical purposes, therefore, expressions for the end-corrections in terms of Shear number and edge geometry are provided. The relative error of these expressions is <3% compared to the numerical results. 

  • 115.
    Ternström, Sten
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Tal, musik och hörsel, TMH.
    Normalized time-domain parameters for electroglottographic waveforms2019Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 146, nr 1, s. EL65-EL70, artikkel-id 1.5117174Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The electroglottographic waveform is of interest for characterizing phonation non-invasively. Existing parameterizations tend to give disparate results because they rely on somewhat arbitrary thresholds and/or contacting events. It is shown that neither are needed for formulating a normalized contact quotient and a normalized peak derivative. A heuristic combination of the two resolves also the ambiguity of a moderate contact quotient, with regard to vocal fold contacting being firm versus weak or absent. As preliminaries, schemes for electroglottography signal preconditioning and time-domain period detection are described that improve somewhat on similar methods. The algorithms are simple and compute quickly.

  • 116.
    Ternström, Sten
    KTH, Tidigare Institutioner (före 2005), Tal, musik och hörsel.
    Preferred self-to-other ratios in choir singing1999Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 105, nr 6, s. 3563-3574Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Choir singers need to hear their own voice in an adequate self-to-other ratio (SOR) over the rest ofthe choir. Knowing singers’ preferences for SOR could facilitate the design of stages and of choral formations. In an experiment to study the preferred SOR, subjects sang sustained vowels together with synthesized choir sounds, whose loudness tracked that of their own voice. They could control the SOR simply by changing their distance to the microphone. At the most comfortable location, the SOR was measured. Experimental factors included unison and four-part tasks, three vowels and two levels of phonation frequency. The same experiment was run four times, using sopranos, altos, tenors, and basses, with stimulus tones adapted for each category. The preferred self-to-other ratios were found to be similar to SORs measured previously in actual performance, if a little higher. Preferences were quite narrow, typically +/-2 dB for each singer, but very different from singer to singer, with intrasubject means ranging from -1 to +15 dB. There was no significant difference between the unison and the four-part tasks, although this might have been caused by systematic differences in the stimulus sounds. Some effects of phonation frequency and vowel were significant, but interdependent and difficult to interpret. The results and their relevance to live choir singing are discussed.

  • 117.
    Ternström, Sten
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH, Musikakustik.
    Bohman, M.
    Södersten, M.
    Loud speech over noise: Some spectral attributes, with gender differences2006Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 119, nr 3, s. 1648-1665Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In seeking an acoustic description of overloaded voice, simulated environmental noise was used to elicit loud speech. A total of 23 adults, 12 females and 11 males, read six passages of 90 s duration, over realistic noise presented over loudspeakers. The noise was canceled out, exposing the speech signal to analysis. Spectrum balance (SB) was defined as the level of the 2-6 kHz band relative to the 0.1-1 kHz band. SB averaged across many similar vowel segments became less negative with increasing sound pressure level (SPL), as described in the literature, but only at moderate SPL. At high SPL, SB exhibited a personal saturation point, above which the high-band level no longer increased faster than the overall SPL, or even stopped increasing altogether, on average at 90.3 dB WO cm) for females and 95.5 dB for males. Saturation occurred 6-8 dB; below the personal maximum SPL, regardless of gender. The loudest productions were often characterized by a relative increase in low-frequency energy, apparently in a sharpened first formant. This suggests a change of vocal strategy when the high spectrum can rise no further. The progression of SB with SPL was characteristically different for individual subjects.

  • 118.
    Ternström, Sten
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH, Musikakustik.
    Cabrera, D.
    Davis, P.
    Self-to-other ratios measured in an opera chorus in performance2005Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 118, nr 6, s. 3903-3911Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Four volunteer members of the chorus of Opera Australia, representing four different voice categories, wore binaural pairs of wireless microphones during a penultimate dress rehearsal on the Opera Theater stage of the Sydney Opera House. From the recordings, data were obtained oil sound levels and on the self-to-other ratios (SORs). The sound levels were comparable to those found in loud music in chamber choir performance. The average SOR ranged from +10 to +15 dB. Compared to chamber choirs in other types of room, the SOR values were high. On a separate occasion, the stage support parameters ST1 (early reflections) and ST2 (late reflections) were measured over the whole stage area. STI was about -16 dB, which is typical for opera stages, and -20 dB for ST2, which is unusually low. It is concluded that the SOR in the opera chorus depends mostly on choir formation, which is highly variable, and that an opera chorus artist generally can hear his or her own voice very well, but little of the others and of the orchestra. This was confirmed by informal listening to the recordings.

  • 119.
    Ternström, Sten
    et al.
    KTH, Tidigare Institutioner (före 2005), Talöverföring och musikakustik.
    Sundberg, Johan
    KTH, Tidigare Institutioner (före 2005), Talöverföring och musikakustik.
    Intonation precision of choir singers1988Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 84, nr 1, s. 59-69Artikkel i tidsskrift (Fagfellevurdert)
  • 120. Titze, Ingo R.
    et al.
    Baken, Ronald J.
    Bozeman, Kenneth W.
    Granqvist, Svante
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Grundläggande naturvetenskap.
    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, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH.
    Wolfe, Joe
    Toward a consensus on symbolic notation of harmonics, resonances, and formants in vocalization2015Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 137, nr 5, s. 3005-3007Artikkel i tidsskrift (Fagfellevurdert)
  • 121.
    Van der Kelen, Christophe
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Strukturakustik.
    Göransson, Peter
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Numerisk akustik.
    Identification of the full anisotropic flow resistivity tensor for multiple glass wool and melamine foam samples2013Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 134, nr 6, s. 4659-4669Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The flow resistivity tensor, which is the inverse of the viscous permeability tensor, is one of the most important material properties for the acoustic performance of porous materials used in acoustic treatments. Due to the manufacturing processes involved, these porous materials are most often geometrically anisotropic on a microscopic scale, and for demanding applications, there is a need for improved characterization methods. This paper discusses recent refinements of a method for the identification of the anisotropic flow resistivity tensor. The inverse estimation is verified for three fictitious materials with different degrees of anisotropy. Measurements are performed on nine glass wool samples and seven melamine foam samples, and the anisotropic flow resistivity tensors obtained are validated by comparison to measurements performed on uni-directional cylindrical samples, extracted from the same, previously measured cubic samples. The variability of flow resistivity in the batch of material from which the glass wool is extracted is discussed. The results for the melamine foam suggest that there is a relation between the direction of highest flow resistivity, and the rise direction of the material.

  • 122.
    Weng, Chenyang
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    Boij, Susann
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    Hanifi, Ardeshir
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    The attenuation of sound by turbulence in internal flows2013Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 133, nr 6, s. 3764-3776Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The attenuation of sound waves due to interaction with low Mach number turbulent boundary layers in internal flows (channel or pipe flow) is examined. Dynamic equations for the turbulent Reynolds stress on the sound wave are derived, and the analytical solution to the equation provides a frequency dependent eddy viscosity model. This model is used to predict the attenuation of sound propagating in fully developed turbulent pipe flow. The predictions are shown to compare well with the experimental data. The proposed dynamic equation shows that the turbulence behaves like a viscoelastic fluid in the interaction process, and that the ratio of turbulent relaxation time near the wall and the sound wave period is the parameter that controls the characteristics of the attenuation induced by the turbulent flow.

  • 123.
    Zea, Elias
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Teknisk mekanik, Strömningsmekanik och Teknisk Akustik, Marcus Wallenberg Laboratoriet MWL.
    Brandão, Eric
    Acoustical Engineering & Civil Engineering Graduate Program, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, 97050-140, Brazil.
    Nolan, Mélanie
    School of Architecture, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
    Cuenca, Jacques
    Siemens Industry Software, Interleuvenlaan 68, BE-3001 Leuven, Belgium.
    Andén, Joakim
    KTH, Skolan för teknikvetenskap (SCI), Matematik (Inst.), Matematik (Avd.).
    Svensson, U. Peter
    Department of Electronic Systems, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
    Sound absorption estimation of finite porous samples with deep residual learning2023Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 154, nr 4, s. 2321-2332Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This work proposes a method to predict the sound absorption coefficient of finite porous absorbers using a residual neural network and a single-layer microphone array. The goal is to mitigate the discrepancies between predicted and measured data due to the finite-size effect for a wide range of rectangular absorbers with varying dimensions and flow resistivity and for various source-receiver locations. Data for training, validation, and testing are generated with a boundary element model consisting of a baffled porous layer on a rigid backing using the Delany–Bazley–Miki model. In effect, the network learns relevant features from the array pressure amplitude to predict the sound absorption as if the porous material were infinite. The method’s performance is quantified with the error between the predicted and theoretical sound absorption coefficients and compared with the two-microphone method. For array distances close to the porous sample, the proposed method performs at least as well as the two-microphone method and significantly better than it for frequencies below 400 Hz and small absorber sizes (e.g., 20 x 20 cm2). The significance of the study lies in the possibility of measuring sound absorption on-site in the presence of strong edge diffraction.

    Fulltekst (pdf)
    fulltext
  • 124.
    Zea, Elias
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet. Eindhoven University of Technology, Department of Mechanical Engineering.
    On modified wavenumber filters for rail contribution estimations2018Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 144, s. EL286-EL289Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This brief communication exposes an overview of various wavenumber filters to separate the rail contribution to pass-by noise via the wave signature extraction method [Zea, Manzari, Squicciarini, Feng, Thompson, and Lopez Arteaga, J. Sound Vib. 409, 24–42 (2017)]. It has been found that the originally proposed filters underesti- mate the rail noise at frequencies above 1.6 kHz due to the presence of higher-order wave families that is unaccounted for. The goal of this let- ter is thus to propose and examine different filter functions that can cap- ture such waves, and to assess whether the rail contribution estimations can be improved.

    Fulltekst (pdf)
    fulltext
  • 125.
    Zea, Elias
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Lopez Arteaga, Ines
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg, MWL Marcus Wallenberg Laboratoriet.
    Single-layer array method to reconstruct extended sound sources facing a parallel reflector2017Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 141, nr 5, s. 3984-3984Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    The accuracy of sound field reconstruction methods with single-layer microphone arrays is subject to the room or enclosure in which the measurements take place. Thus, the authors recently introduced a single-layer method that can be employed to reconstruct compact sources in the presence of a reflecting surface that is parallel to the array. Now the authors propose a method conceived for extended planar sources such as baffled plates facing a parallel reflector. The method is based on a wavenumber-domain function describing the propagation paths between the source, the reflector and the array. The free-space sound field radiated by the source is then recovered by means of a regularized inversion of the propagation function. Numerical simulations are performed in order to assess the method's performance and potential for source reconstructions. The results are promising and point towards future experimental validation.

  • 126.
    Åberg, Mats
    et al.
    KTH, Tidigare Institutioner (före 2005), Hållfasthetslära.
    Gudmundson, Peter
    KTH, Tidigare Institutioner (före 2005), Hållfasthetslära.
    The usage of standard finite element codes for computation of dispersion relations in materials with periodic microstructure1997Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 102, nr 4, s. 2007-2013Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A method with which standard finite element programs can be used to compute dispersion relations in periodic composites is proposed. The method is applied to two composite microstructures: a two-phase laminate and a fiber composite. The dispersion relations computed for the laminate are compared with a known analytical solution and the agreement is very good. The dispersion relations computed for the fibrous composite are compared with an existing approximate model and experimental results from the literature. The agreement between the approximate model, the experiments, and the computations is very good in the wave guide case and satisfactory for the wave reflect case.

  • 127.
    Öberg, Fredrik
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH, Musikakustik.
    Askenfelt, Anders
    KTH, Skolan för datavetenskap och kommunikation (CSC), Tal, musik och hörsel, TMH, Musikakustik.
    Acoustical and perceptual influence of duplex stringing in grand pianos2012Inngår i: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 131, nr 1, s. 856-871Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study investigates the acoustical and perceptual influence of the string parts outside the speaking length in grand pianos (front and rear duplex strings). Acoustical measurements on a grand piano in concert condition were conducted, measuring the fundamental frequencies of all main and duplex strings in the four octaves D4-C8. Considerable deviations from the nominal harmonic relations between the rear duplex and main string frequencies, as described by the manufacturer in a patent, were observed. Generally the rear duplex strings were tuned higher than the nominal harmonic relations with average and median deviations approaching _50 cent. Single keys reached +190 and -100 cent. The spread in deviation from harmonic relations within trichords was also substantial with average and median values around 25 cent, occasionally reaching 60 cent. Contributions from both front and rear duplex strings were observed in the bridge motion and sound. The audibility of the duplex strings was studied in an ABX listening test. Complete dampening of the front duplex was clearly perceptible both for an experiment group consisting of musicians and a control group with naive subjects. The contribution from the rear duplex could also be perceived, but less pronounced.

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