Changes in sound pressure and fundamental frequency contours following changes in hearing status

Abstract

Sound-pressure level ͑SPL͒ and fundamental frequency (F0) contours were obtained from four postlingually deafened adults who received cochlear implants and from a subject with Neurofibromatosis-2 ͑NF2͒ who had her hearing severely reduced following surgery to remove an auditory-nerve tumor and to implant an auditory brainstem implant. SPL and F0 contours for each phrase in passages read before and after changes in hearing were averaged over repeated readings and then normalized with respect to the highest SPL or F0 value in the contour. The regularity of each average contour was measured by calculating differences between successive syllable means and averaging the absolute values of these differences. With auditory feedback made available, the cochlear implant user with the least contour variation preimplant showed no change but all of the remaining speakers produced less variable F0 contours and three also produced less variable SPL contours. In complementary fashion, when the NF2 speaker had her auditory feedback severely reduced, she produced more variable F0 and SPL contours. The results are interpreted as supporting a dual-process theory of the role of auditory feedback in speech production, according to which one role of self-hearing is to monitor transmission conditions, leading the speaker to make changes in speech postures aimed at maintaining intelligibility.

Effects of masking noise on vowel and sibilant contrasts in normal-hearing speakers and postlingually deafened cochlear implant users

“…When the speaker perceives a deterioration in signal to noise ratio, either because of reduced signal levels or increased noise levels, that speaker will increase speaking sound level ͑Lane and Tranel, 1971;Van Summers et al, 1988;Black, 1951;Hanley and Steer, 1949;Tartter et al, 1993͒ andsegmental duration ͑Van Summers et al, 1988;Hanley and Steer, 1949͒. Utterances produced under such adverse conditions are more intelligible than those produced under optimal transmission conditions ͑Van Summers et al, 1988;Dreher and O'Neill, 1958;Peters, 1955;Draegert, 1951͒. These changes in sound level and durations under adverse conditions are consistent with those produced under instructions to speak clearly, as Lane et al ͑1997͒ andVan Summers et al ͑1988͒ noted. ͑There are, however, considerable differences among talkers: Hazan and Markham, 2004;Ferguson, 2004;Perkell et al, 2002;Gagné and Tye-Murray, 1994.͒ Under clear speech instructions, vowel amplitudes and durations increase ͑Picheny et al., 1986;Liu et al, 2004͒. Furthermore, like speaking under adverse conditions, clear speech is also more intelligible than conversational speech ͑Picheny et , 1986Chen et al, 1983;Liu et al, 2004;Krause and Braida, 2003;Payton et al, 1994;Ferguson and Kewley-Port, 2002͒.…”

An acoustic analysis of laughter produced by congenitally deaf and normally hearing college students

“…2͒, although they were not twice as high as prototypical values from normative speech ͑e.g., 120 and 220 Hz for males and females, respectively; Baken and Orlikoff, 1999͒. Mean F 0 values in the speech of deaf individuals are thought to be similar to that of hearing talkers, but also vary significantly by individual talker ͑e.g., Lane et al, 1997͒. Finding more or less comparable F 0 values in the laughter of deaf and hearing males, but lower F 0 's in the laughter of deaf versus hearing females is therefore somewhat difficult to interpret.…”

Postlearning Consolidation of Birdsong: Stabilizing Effects of Age and Anterior Forebrain Lesions

“…For example, spectral properties of speech can be degraded such that fundamental frequency varies abnormally over time and spectra of individual syllables become flattened and noisy (Kirk and Edgerton, 1983;Lane and Webster, 1991;Cowie and Douglas-Cowie, 1992;Lane et al, 1997). Likewise, sequential organization of speech can be disrupted such that syllables are inappropriately dropped, repeated, or substituted one for another.…”