Sharon R. Garber

Inhibiting the Lombard effect

The Lombard effect is the tendency to increase ones vocal intensity in noise. The present study reports three experiments that test the robustness of the Lombard effect when speakers are given instructions and training with visual feedback to help suppress it. The Lombard effect was found to be extremely stable and robust. Instructions alone had little influence on the response to the noise among untrained speakers. When visual feedback correlated with vocal intensity was presented, however, subjects could inhibit the Lombard response. Furthermore, the inhibition remained after the visual feedback was removed. The data are interpreted as indicating that the Lombard response is largely automatic and not ordinarily under volitional control. When subjects do learn to suppress the effect, they seem to do so by changing overall vocal level rather than their specific response to the noise.

The effects on speech of surgical premaxillary osteotomy

Patients were tested before and after undergoing surgical premaxillary osteotomy for correction of skeletal and soft-tissue discrepancies. Both structural and speech measurements were made before surgery and for a year after surgery. The role of hearing and oral sensation in adaptation to surgery was evaluated. Immediately after surgery, speech was disrupted. Distortions of /s/ predominated. However, there were non long-term effects on speech. Hearing and oral sensation played little role in adaptation.

Auditory feedback and speech development.

Publisher Summary This chapter evaluates the role of feedback, particularly auditory feedback, in the development of speech in children. In the recent enthusiasm for exploring rule-governed bases of linguistic competence, the fact that speech is a highly coordinated motor skill has been almost ignored. Competence theories have ruled the imagination of researchers whereas performance data have been grudgingly accepted as the imperfect source from which competence theories are derived. As important as linguistic considerations are, they inevitably take form through an expressive system such as speech, writing, or signing, and such a system could scarcely function without the contribution of feedback, at least during certain stages of development. Under normal circumstances, speech clearly is multiply determined. Speakers acquire the language to which they have been exposed in the presence of different kinds of listeners and in a variety of social and physical situations. Although it is a motor skill, speech is the expression of linguistic codes and communication needs. Speakers talk louder in noise and also to impress a listener with their determination. Choice of words, speech rate, and inflectional pattern are all multiply determined, reflecting the contributions of social and physical variables, as well as the physiological constraints of the speech system. The relationship between forms of feedback and the various parameters of speech production are well worth exploring in future research. The area is an exciting one, as it pertains both to normal and deviant speech development.

The effects of feedback filtering on speaker intelligibility.

Subjects read intelligibility tests while hearing their voices low- or high-pass filtered. The tests were presented to listeners to assess speaker intelligibility. Feedback filtering had a variable effect on intelligibility. When speakers were permitted to increase their intensities in low-pass filtering conditions, their intelligibility also increased. Intelligibility did not increase when intensity was controlled. These results do not support the hypothesis that speakers modulate their voices in order to maintain intelligible communication with a presumed listener. IT is suggested instead that speakers alter their intensities in order to regulate the loudness of their voices in their own ears.

A comparison of listener and speaker perception of nasality

The relationship between speaker and listener perception of nasality was investigated by having speakers judge their own productions as they vocalized. The productions were taped and played to listeners who judged the speakers nasality. In part one, speakers used a magnitude production procedure and both speakers and listeners rated nasality, using a ratio scale. Output from an accelerometer placed on the speakers nose provided a measure of nasalization. Self‐perception grew approximately as the 4.4 power of nasalization. Listener perception grew as the 2.2 power of nasalization. Thus, self‐perception of nasality grew twice as rapidly as listener perception for a given increase in nasalization. In part two, both listeners and speakers used a magnitude‐estimation procedure. The exponents for the power functions for self and listener perception were 3.6 and 1.7, respectively. The 2 to 1 relationship between self and listener perception of nasality held when different procedures were used. The 2 to 1 ratio...