Inaccurate but predictable: Vocal-tract length estimation and gender stereotypes in height perception

Research suggests human listeners are not very accurate in assessing the size of adults from their speech, though they appear to be consistent in their judgments across listeners. Two experiments were conducted to investigate the importance of the higher formants for providing consistent height judgments, how consistent these height judgments are across replications, and the role of f0 and social knowledge in maintaining the stability of apparent speaker height judgments. Listeners were presented with syllables produced by 30 adult male and female speakers, and were asked to identify the word, the gender of the speaker, and the height of the speaker. In a second experiment, listeners were presented with voiced and (synthetic) whispered speech and asked to provide the same responses. Results indicate that speakers use acoustic cues in largely predictable ways, leading to consistent apparent height judgments when averaged across listeners. However, the behavior of individual listeners is unpredictable, and the accuracy of apparent height judgments with respect to veridical heights is low. Finally, results suggest that non-acoustic social knowledge regarding the expected sizes of adult males and females play an important role in the determination of apparent height from speech.