The Lombard Sign and the Role of Hearing in Speech

Abstract

Lombard noted in 1911 that a speaker changes his voice level similarly when the ambient noise level increases, on the one hand, and when the level at which he hears his own voice (his sidetone) decreases, on the other. We can now state the form of these two functions, show that they are related to each other and to the equal-sensation function for imitating speech or noise loudness, and account for their form in terms of the underlying sensory scales and the hypothesis that the speaker tries to maintain a speech-to-noise ratio favorable for communication. Perturbations in the timing and spectrum of sidetone also lead the speaker to compensate for the apparent deterioration in his intelligibility. Such compensations reflect direct and indirect audience control of speech, rather than its autoregulation by sidetone. When not harassed by prying experimenters or an unfavorable acoustic environment, the speaker need no more listen to himself while speaking than he need speak to himself while listening.

Teachers' Voice Use in Teaching Environments: A Field Study Using Ambulatory Phonation Monitor

“…The results showed that both groups were equally affected by noise and behaved in accordance with the Lombard effect 17 , increasing their voice intensity with increasing BNL.…”

“…Thus, it is important to consider the effect of the activity noise on the teacher's voice. The Lombard effect 17 describes the influence of surrounding noise on the voice. The speaker automatically raises the SPL and changes the spectral contents of the voice signal as the noise level increases.…”

Neural mechanisms underlying auditory feedback control of speech

“…Our ability to speak effectively when noise completely masks auditory feedback (Lane and Tranel, 1971;Pittman and Wiley, 2001) and the maintained intelligibility of postlingually deafened individuals (Cowie and Douglas-Cowie, 1983;Lane and Webster, 1991) are further evidence of feedforward control mechanisms. The existence of stored feedforward motor commands that are tuned over time by auditory feedback is provided by studies of sensorimotor adaptation (Houde and Jordan, 2002;Jones and Munhall, 2002;Jones and Munhall, 2005;Purcell and Munhall, 2006a).…”

“…Analogously, auditory information plays an important role in monitoring vocal output and achieving verbal fluency (Lane and Tranel, 1971;Cowie and Douglas-Cowie, 1983). Auditory feedback is crucial for on-line correction of speech production (Lane and Tranel, 1971;Xu et al, 2004;Purcell and Munhall, 2006b) and for the development and maintenance of stored motor plans (Cowie and Douglas-Cowie, 1983;Purcell and Munhall, 2006a;Villacorta, 2006).…”

Neural correlates of verbal feedback processing: An fMRI study employing overt speech

“…Participants were instructed not to be concerned with audibility to minimize speech-related movement; they were told not to over-articulate or speak loudly. Furthermore, they were made aware of the automatic tendency to increase the loudness of their voice in the presence of noise (Lombard effect [Lane and Tranel, 1971]) and instructed to speak at the same volume throughout the experiment. Finally, in the covert picture-naming condition (PNcovert), the participants were asked to internally generate the picture name without producing it aloud or moving their lips.…”