Effects of deafness on acoustic characteristics of American English tense/lax vowels in maternal speech to infants

Abstract

Recent studies have demonstrated that mothers exaggerate phonetic properties of infant-directed (ID) speech. However, these studies focused on a single acoustic dimension (frequency), whereas speech sounds are composed of multiple acoustic cues. Moreover, little is known about how mothers adjust phonetic properties of speech to children with hearing loss. This study examined mothers' production of frequency and duration cues to the American English tense/lax vowel contrast in speech to profoundly deaf (N ¼ 14) and normal-hearing (N ¼ 14) infants, and to an adult experimenter. First and second formant frequencies and vowel duration of tense (/i/, /u/) and lax (/I/, /U/) vowels were measured. Results demonstrated that for both infant groups mothers hyperarticulated the acoustic vowel space and increased vowel duration in ID speech relative to adult-directed speech. Mean F2 values were decreased for the /u/ vowel and increased for the /I/ vowel, and vowel duration was longer for the /i/, /u/, and /I/ vowels in ID speech. However, neither acoustic cue differed in speech to hearing-impaired or normal-hearing infants. These results suggest that both formant frequencies and vowel duration that differentiate American English tense/lx vowel contrasts are modified in ID speech regardless of the hearing status of the addressee.

Vowel Space Characteristics of Speech Directed to Children With and Without Hearing Loss

“…Recent studies have presented contradictory results on the degree of vowel space expansion in ID speech to populations both with and without hearing impairment (Cristia & Seidl, 2014;Englund & Behne, 2006;Kondaurova et al, 2012;C. Lam & Kitamura, 2010, 2012.…”

“…Several studies have demonstrated no enhancement of the distance between vowel categories and/or expansion of the acoustic vowel space area in speech to children with normal hearing compared with AD speech (Cristia & Seidl, 2014;Englund & Behne, 2006). Although evidence of vowel space expansion exists when a talker is aware that an adult listener has a hearing impairment (Ferguson & Kewley-Port, 2002;Picheny, Durlach, & Braida, 1986), partial or no vowel space expansion was observed in speech to children with hearing impairment (Kondaurova et al, 2012;C. Lam & Kitamura, 2010).…”

“…Despite evidence regarding the importance of ID speech for development in children with normal hearing, researchers have only recently started to examine the properties of linguistic input to children with hearing loss (Bergeson, Miller, & McCune, 2006;Kondaurova & Bergeson, 2011;Kondaurova, Bergeson, & Dilley, 2012;Kondaurova, Bergeson, & Xu, 2013;C. Lam & Kitamura, 2010).…”

“…Research with children who were prelingually deaf prior to cochlear implantation demonstrated an expanded vowel space in ID speech for only a subset of vowels (/u/ and /ɪ/; Kondaurova et al, 2012). In order to investigate the effect of hearing impairment on vowel space in ID speech with more participants, C. Lam and Kitamura (2012) simulated hearing loss in infants with normal hearing.…”

Spontaneous vocal matching in mothers and their hearing impaired infants with cochlear implants : a quantitative analysis.

“…This agrees with previous literature that shows maternal speech to HI infants is affected by infant hearing loss (Chen, 1996;Cheskin, 1981;Cross, JohnsonMorris, & Nienhuys, 1980;Kondaurova & Bergeson, 2011;Kondaurova et al, 2012;Kondaurova, Bergeson, & Kitamura, 2013;Kondaurova, Bergeson, & Xu, 2013;Kondaurova et al, 2015;Kondaurova, Blank, Zheng, Abu Zhaya, & Seidl, 2016;Nienhuys, Cross, & Horsborough, 1984;Wieland, Burnham, Kondaurova, Bergeson, & Dilley, 2015). Previous research has demonstrated that mothers use shorter utterances, exaggerated pitch characteristics, and a slower speaking rate when interacting with their HI infants (Kondaurova, Bergeson, & Xu, 2013).…”