When presented with voices, we make rapid, automatic judgements of social traits such as trustworthiness—and such judgements are highly consistent across listeners. However, it remains unclear whether voice-based first impressions actually influence behaviour towards a voice’s owner, and—if they do—whether and how they interact over time with the voice owner’s observed actions to further influence the listener’s behaviour. This study used an investment game paradigm to investigate (1) whether voices judged to differ in relevant social traits accrued different levels of investment and/or (2) whether first impressions of the voices interacted with the behaviour of their apparent owners to influence investments over time. Results show that participants were responding to their partner’s behaviour. Crucially, however, there were no effects of voice. These findings suggest that, at least under some conditions, social traits perceived from the voice alone may not influence trusting behaviours in the context of a virtual interaction.