Index of content:
Volume 122, Issue 5, November 2007
- SPEECH PERCEPTION 
Learning English vowels with different first-language vowel systems: Perception of formant targets, formant movement, and duration122(2007); http://dx.doi.org/10.1121/1.2783198View Description Hide Description
This study examined whether individuals with a wide range of first-language vowel systems (Spanish, French, German, and Norwegian) differ fundamentally in the cues that they use when they learn the English vowel system (e.g., formant movement and duration). All subjects: (1) identified natural English vowels in quiet; (2) identified English vowels in noise that had been signal processed to flatten formant movement or equate duration; (3) perceptually mapped best exemplars for first- and second-language synthetic vowels in a five-dimensional vowel space that included formant movement and duration; and (4) rated how natural English vowels assimilated into their vowel categories. The results demonstrated that individuals with larger and more complex first-language vowel systems (German and Norwegian) were more accurate at recognizing English vowels than were individuals with smaller first-language systems (Spanish and French). However, there were no fundamental differences in what these individuals learned. That is, all groups used formant movement and duration to recognize English vowels, and learned new aspects of the English vowel system rather than simply assimilating vowels into existing first-language categories. The results suggest that there is a surprising degree of uniformity in the ways that individuals with different language backgrounds perceive second language vowels.
122(2007); http://dx.doi.org/10.1121/1.2781580View Description Hide Description
The goal of this study was to measure the ability of adult hearing-impaired listeners to discriminate formant frequency for vowels in isolation, syllables, and sentences. Vowelformantdiscrimination for F1 and F2 for the vowels /ɪ ε æ ʌ/ was measured. Four experimental factors were manipulated including linguistic context (isolated vowels, syllables, and sentences), signal level (70 and SPL),formant frequency, and cognitive load. A complex identification task was added to the formantdiscrimination task only for sentences to assess effects of cognitive load. Results showed significant elevation in formant thresholds as formant frequency and linguistic context increased. Higher signal level also elevated formant thresholds primarily for F2. However, no effect of the additional identification task on the formantdiscrimination was observed. In comparable conditions, these hearing-impaired listeners had elevated thresholds for formantdiscrimination compared to young normal-hearing listeners primarily for F2. Altogether, poorer performance for formantdiscrimination for these adult hearing-impaired listeners was mainly caused by hearing loss rather than cognitive difficulty for tasks implemented in this study.