The Impact of Visual Estimates of Talker-to-Listener Distance on Fundamental Frequency in Noise

Lombard speech is an involuntary adaptive changes in voicing under the influence of noise. In the current work we examine the relationship between involuntary auditory-speech control, common for the Lombard speech, and voluntary control of phonation which occurs as a result of the visual estimation of the distance to the listener. Fundamental frequencies (F0) were estimated in 9 Russian normally hearing female speakers aged 20–35 years. An increase in F0 was obtained when the communicative conditions became more complex in both increase in surrounding background noise level and growth of talker-to-listener distance cases. In quiet and in noise of 60 and 72 dB the increase in talker-to-listener distance led to F0 increments of 14, 18 and 15 Hz, which did not differ significantly from each other (p > 0.05, n = 288). When the communicative distance held constant, babble noise of different levels led to significantly different values of ΔF0: for 1 m distance – 14 and 32 Hz (p < 0.001, n = 288), and for 4 m – 18 and 33 Hz (p < 0.001, n = 288), respectively. The data obtained evidence independent and additive impact of noise and communicative distance on phonation.