How voice similarity influences our thinking

Oliver Jaggy, former member of the Realistic Depictions lab at the IWM, recently successfully completed his doctorate with the defence of his thesis on the influence of voice similarity on cognitive processes.

In his dissertation entitled ‘The Influence of Voice Similarity on Cognitive Processes’, he investigated how perceived voice similarity influences our social evaluations and cognitive processes – a field of research that is becoming increasingly relevant with the growing personalisation of speech systems. The starting point is the observation that text-to-speech systems today generate voices that are deceptively similar to human speech.

Differentiated results

The central question is: Can such synthetic voices, which resemble our own, promote sympathy and trust and even influence our decisions? The results are as exciting as they are nuanced. Voices that resemble our own are indeed perceived as more likeable and trustworthy. In decision-making processes, however, there was no clear advantage for similar voices – instead, complex interaction effects occurred that point to subtle attention processes.

The findings on the so-called illusory truth effect are particularly controversial: similar voices increase the likelihood that false statements will be believed to be true. Thus, voice similarity not only influences social evaluations, but also fundamental cognitive processes of truth attribution. With these findings, the dissertation makes an important contribution to research on auditory similarity and opens up exciting perspectives for the use of personalised speech systems in the future.