Accuracy of speaker's self-estimation of their own voice

Speakers possess the ability to unconsciously adjust their vocal level according to the physical distance between conversants and the social context of a conversation. However, it remains unclear whether the self-estimation of one's own voice loudness, which the speaker assumes the listener is hearing, is physically accurate. This study quantitatively assessed this accuracy and investigated how psychological factors are related, and whether the discrepancy lies in the voice production itself. In Experiment 1, participants vocalized greetings or neutral sentences, and their actual level (Vocalization) was compared to their estimated listener level (Estimation). Results showed that speakers underestimated their own voice by around 10 dB, speaking at a significantly louder level than they assumed. Furthermore, higher social anxiety correlated with a smaller discrepancy, reflecting more accurate vocalization. Experiment 2 assessed the role of voice production in the discrepancy by playing participants their own recorded voice instead of participants speaking aloud. When speaking was absent, the difference between the actual recorded sound and the assumed level was 0.4 dB, suggesting that the observed over-vocalization is not caused by cognitive errors (e.g., perception of distance) but by physiological inhibitory mechanisms specific to the act of vocalization, such as the middle-ear reflex and speech-induced suppression.