Duration discrimination of speech and tonal complex stimuli by normally hearing and hearing-impaired listeners

Abstract

The ability to discriminate changes in the length of vowels and tonal complexes (filled intervals) and in the duration of closure in stop consonants and gaps in tonal complexes (unfilled intervals) was studied in three normally hearing and seven severely hearing-impaired listeners. The speech stimuli consisted of the vowels (i, I, u, U, a, A) and the consonants (p, t, k), and the tonal complexes consisted of digitally generated sinusoids at 0.5, 1, and 2 kHz. The signals were presented at conversational levels for each listener group, and a 3IFC adaptive procedure was used to estimate difference limens (DLs). The DLs for speech were similar to those for tonal complex stimuli in both the filled and unfilled conditions. Both normally and impaired-hearing listeners demonstrated greater acuity for changes in the duration of filled than unfilled intervals. Mean thresholds for filled intervals obtained from normally hearing listeners were smaller than those obtained from hearing-impaired listeners. For unfilled intervals, however, the difference between listener groups was not significant. A few hearing-impaired listeners demonstrated temporal acuity comparable to that of normally hearing listeners for several listening conditions. Implications of these results are discussed with regard to speech perception in normally and impaired-hearing individuals.

The perception of intonation questions and statements in Cantonese

“…All six tones produced by speaker M1, and four of the six tones (tones 25, 33, 23, and 22) produced by speaker F1 had longer syllable duration in questions (ranging from 6 to 86 ms) than in statements, but speaker F1 produced longer syllable duration in statements for tones 55 (1 ms) and 21 (15 ms). Both Lehiste (1970) and Bochner et al (1988) reported a difference limen of about 40 ms for a standard signal of about 300 ms. A comparison of the duration of the final syllable within the 36 statement-question pairs (i.e., the same utterance produced once as a statement and once as a question by the same speaker) showed that 61% of these pairs differed by less than the 40-ms difference limen. The final syllable of questions was 46-263 ms longer than its counterpart in statements in the remaining 39% statement-question pairs.…”

Effect of intra-phrase position on acceptability of change in segment duration in sentence speech

“…PearsonÕs product-moment correlation coefficients for each listener ranged from À0.08 to 0.26. Bochner et al reported that the absolute jnd of the vowel duration increased with an increase in the vowel duration (Bochner et al, 1988). On the other hand, Klatt et al reported that vowel duration had no significant correlation with the jndÕs of vowel duration (Klatt, 1976), and Kato et al also reported that the original duration had no significant correlation with the vulnerability index (Kato et al, 1998 context might make the influence of the original vowel duration effective while the polysyllabic context reduces or hides it.…”

“…That is, the measure neglects the possibility that the physically same errors may affect a perception differently. Previous studies have reported various factors that affect sensitivity to segmental duration distortion (Bochner et al, 1988;Klatt, 1976;Klatt and Cooper, 1975;Kato et al, 1997Kato et al, , 1998Kato et al, , 2002. In particular, Kato et al systematically analyzed contextual and positional dependency of perceptual sensitivity to segmental duration distortion by using isolated word utterances.…”

Ritmo da escrita e ritmo da fala: congruências e não congruências

“…Abaixo desses traçados pode-se ver a delimitação das palavras emitidas, a partir da qual se constata que não há pausas silenciosas entre as palavras, a não ser entre as duas sequências ternárias, onde há um silêncio de cerca de 240 ms. A duração das seis palavras é semelhante: mesmo a última não difere de forma signfictiva das demais. Além disso, estudos psicoacústicos mostraram que diferenças de duração inferiores a 25 ms não são percebidas na fala (LEHISTE, 1970;BOCHNER;SNELL;MACKENZIE, 1988). Mesmo diferenças maiores podem não ser percebidas no contexto de sua produção real, isto é, fora do laboratório, em que os trechos sonoros são paradigmaticamente comparados e os sujeitos são guiados para prestar atenção aos estímulos no que respeita a duração.…”