Nasal/Oral Vowel Perception in French-Speaking Children With Cochlear Implants and Children With Typical Hearing.

PURPOSE: The present study investigates the perception of vowel nasality in French-speaking children with cochlear implants (CIs; CI group) and children with typical hearing (TH; TH group) aged 4-12 years. By investigating the vocalic nasality feature in French, the study aims to document more broadly the effects of the acoustic limitations of CI in processing segments characterized by acoustic cues that require optimal spectral resolution. The impact of various factors related to children's characteristics, such as chronological/auditory age, age of implantation, and exposure to cued speech, has been studied on performance, and the acoustic characteristics of the stimuli in perceptual tasks have also been investigated. METHOD: Identification and discrimination tasks involving French nasal and oral vowels were administered to two groups of children: 13 children with CIs (CI group) and 25 children with TH (TH group) divided into three age groups (4-6 years, 7-9 years, and 10-12 years). French nasal vowels were paired with their oral phonological counterpart (phonological pairing) as well as to the closest oral vowel in terms of phonetic proximity (phonetic pairing). Post hoc acoustic analyses of the stimuli were linked to the performance in perception. RESULTS: The results indicate an effect of the auditory status on the performance in the two tasks, with the CI group performing at a lower level than the TH group. However, the scores of the children in the CI group are well above chance level, exceeding 80%. The most common errors in identification were substitutions between nasal vowels and phonetically close oral vowels as well as confusions between the phoneme /u/ and other oral vowels. Phonetic pairs showed lower discrimination performance in the CI group with great variability in the results. Age effects were observed only in TH children for nasal vowel identification, whereas in children with CIs, a positive impact of cued speech practice and early implantation was found. Differential links between performance and acoustic characteristics were found within our groups, suggesting that in children with CIs, selective use of certain acoustic features, presumed to be better transmitted by the implant, leads to better perceptual performance. CONCLUSIONS: The study's results reveal specific challenges in children with CIs when processing segments characterized by fine spectral resolution cues. However, the CI children in our study appear to effectively compensate for these difficulties by utilizing various acoustic cues assumed to be well transmitted by the implant, such as cues related to the temporal resolution of stimuli. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25328704.

Phonological and phonetic impairment in aphasic speech: an acoustic study of the voice onset time of six French-speaking aphasic patients.

The aim of the present study is to contribute to the description of the speech production deficits in French-speaking aphasic patients, so as to shed light on their potential phonetic and/or phonological disorders. Acoustic studies of aphasics' speech productions remain relatively infrequent, especially in French, and when entering into the specifics, often lead to inconsistent results. We conducted a multiple-case study on six aphasic patients, four with non-fluent aphasia and two with fluent aphasia. They were administered a variety of language and neuropsychological tasks, then they participated in a customized non-word repetition task. Acoustic analyses of their speech productions were performed, focussing on VOT as the main acoustic correlate of the voicing contrast for oral stops. Other atypicalities in their productions were also classified. Results showed variable and mainly "mixed" phonetic-phonological impairment profiles that differed from the traditional hypotheses made in the literature about the speech deficits to be expected as a function of type of aphasia. Our results support the use of acoustic analyses in order to complete language examination in aphasic patients but also suggest that the frontier between phonological and phonetic impairment is not clear-cut. These outcomes are better accounted for by theories and models postulating close relationships between the phonological and phonetic levels of processing.