Intelligibility of interrupted sentences at subsegmental levels in young normal-hearing and elderly hearing-impaired listeners

Abstract

Although listeners can partially understand sentences interrupted by silence or noise, and their performance depends on the characteristics of the glimpses, few studies have examined effects of the types of segmental and subsegmental information on sentence intelligibility. Given the finding of twice better intelligibility from vowel-only glimpses than from consonants [Kewley-Port et al. (2007). "Contribution of consonant versus vowel information to sentence intelligibility for young normal-hearing and elderly hearing-impaired listeners," J. Acoust. Soc. Am. 122, 2365-2375], this study examined young normal-hearing and elderly hearing-impaired (EHI) listeners' intelligibility of interrupted sentences that preserved four different types of subsegmental cues (steady-states at centers or transitions at margins; vowel onset or offset transitions). Forty-two interrupted sentences from TIMIT were presented twice at 95 dB SPL, first with 50% and second with 70% of sentence duration. Compared to high sentence intelligibility for uninterrupted sentences, interrupted sentences had significant decreases in performance for all listeners, with a larger decrease for EHI listeners. Scores for both groups were significantly better for 70% duration than for 50% but were not significantly different for the type of subsegmental information. Performance by EHI listeners was associated with their high-frequency hearing thresholds rather than with age. Together with previous results using segmental interruption, preservation of vowels in interrupted sentences provides greater benefit to sentence intelligibility compared to consonants or subsegmental cues.