The effects of temporal envelope confusion on listeners' phoneme and word recognition

Abstract

Broadened auditory filters in listeners with hearing loss may result in listeners' increased reliance on temporal envelope cues for understanding speech. Previous data have shown that background noise may affect hearing-impaired (HI) listeners by negatively affecting the temporal envelope cues in speech. The current study investigates additional HI listeners? understanding of vocoded spondees in the presence of fluctuating and stationary background noise. Stimuli were 8- and 32-channel noise vocoded double spondees, high-pass filtered at 1426 Hz. New data confirmed the previous finding that temporal envelope confusion in HI listeners resulted in speech understanding that is poorer in fluctuating noise (at a rate of 4Hz) than in stationary noise. Preliminary analysis suggests HI listeners experience significant envelope confusion for both 8- and 32-channel vocoded stimuli. Additional analysis of phoneme errors suggests that envelope confusion affects HI listeners' perception of both consonants and vowels. Further analysis of j-factors will indicate the relationship of phoneme to whole word understanding for vocoded speech in noise. Results confirm the importance of temporal envelope cues for phoneme and syllable recognition for listeners with hearing loss. © 2013 Acoustical Society of America.