The role of familiarity on within-person age judgements from voices

Listeners can perceive a person’s age from their voice with good accuracy. Studies have usually established this by asking listeners to directly estimate the age of unfamiliar voices. The recordings used mostly include cross-sectional samples of voices, including a people of different ages to cover the age range of interest. Such cross-sectional samples likely not only include cues to age in the sound of the voice but also socio-phonetic cues, encoded in how a person speaks. How accuracy is affected when minimising socio-phonetic cues by sampling the same voice at different timepoints remains largely unknown. Similarly, with the voices in age perception studies being usually unfamiliar to listeners, it is unclear how familiarity with a voice affects age perception. We asked listeners who were either familiar or unfamiliar with a set of voices to complete an age discrimination task: Listeners heard two recordings of the same person’s voice, recorded 15 years apart, and were asked to indicate in which recording the person was younger. Accuracy for both familiar and unfamiliar listeners was above chance. While familiarity advantages were apparent, accuracy was not particularly high: Familiar and unfamiliar listeners were correct for 68.2% and 62.7% of trials respectively (chance = 50%). Familiarity furthermore interacted with the voices included. Overall, our findings indicate that age perception from voices is not a trivial task at all times – even when listeners are familiar with a voice. We discuss our findings in light of how reliable voice may be as a signal for age.