Recognition of Interrupted Speech, Text, and Text-Supplemented Speech by Older Adults: Effect of Interruption Rate.

PURPOSE: Studies of speech and text interruption indicate that the interruption rate influences the perceptual information available, from whole words at slow rates to subphonemic cues at faster interruptions rates. In young adults, the benefit obtained from text supplementation of speech may depend on the type of perceptual information available in either modality. Age commonly reduces temporal aspects of information processing, which may influence the benefit older adults obtain from text-supplemented speech across interruption rates. METHOD: Older adults were tested unimodally and multimodally with spoken and printed sentences that were interrupted by silence or white space at various rates. RESULTS: Results demonstrate U-shaped performance-rate functions for all modality conditions, with minimal performance around interruption rates of 2-4 Hz. Comparison to previous studies with younger adults indicates overall poorer recognition for interrupted materials by the older adults. However, as a group, older adults can integrate information between the two modalities to a similar degree as younger adults. Individual differences in multimodal integration were noted. CONCLUSION: Overall, these results indicate that older adults, while demonstrating poorer overall performance in comparison to younger adults, successfully combine distributed partial information across speech and text modalities to facilitate sentence recognition.

Comparing Speech Recognition for Listeners With Normal and Impaired Hearing: Simulations for Controlling Differences in Speech Levels and Spectral Shape.

Purpose This study investigated methods used to simulate factors associated with reduced audibility, increased speech levels, and spectral shaping for aided older adults with hearing loss. Simulations provided to younger normal-hearing adults were used to investigate the effect of sensation level, speech presentation level, and spectral shape in comparison to older adults with hearing loss. Method Measures were assessed in quiet, steady-state noise, and speech-modulated noise. Older adults with hearing loss listened to speech that was spectrally shaped according to their hearing thresholds. Younger adults with normal hearing listened to speech that simulated the hearing-impaired group's (a) reduced audibility, (b) increased speech levels, and (c) spectral shaping. Group comparisons were made based on speech recognition performance and masking release. Additionally, younger adults completed measures of listening effort and perceived speech quality to assess if differences across simulations in these outcome measures were similar to those for speech recognition. Results Across the various simulations employed, testing in the presence of a threshold matching noise best matched differences in speech recognition and masking release between younger and older adults. This result remained consistent across the other two outcome measures. Conclusions A combination of audibility, speech level, and spectral shape factors is required to simulate differences between listeners with normal and impaired hearing in recognition, listening effort, and perceived speech quality. The use of spectrally shaped and amplified speech in the presence of threshold matching noise best provided this simulated control. Supplemental Material https://doi.org/10.23641/asha.13224632.

Combining partial information from speech and text.

The current study investigated how partial speech and text information, distributed at various interruption rates, is combined to support sentence recognition in quiet. Speech and text stimuli were interrupted by silence and presented unimodally or combined in multimodal conditions. Across all conditions, performance was best at the highest interruption rates. Listeners were able to gain benefit from most multimodal presentations, even when the rate of interruption was mismatched between modalities. Supplementing partial speech with incomplete visual cues can improve sentence intelligibility and compensate for degraded speech in adverse listening conditions. However, individual variability in benefit depends on unimodal performance.