Effect of rate altered perception of deep band modulated phrase in noise from normal hearing younger and older adult groups

Purpose: To evaluate the effect of speaking rate on speech perception with unprocessed (UP) and envelope enhancement in noise on normal hearing younger adults (YAG) and older adults (OAG). Method: A purposive sampling with repeated measures research design was adopted to evaluate envelope enhancement on speech perception in adverse listening condition. Study samples: Thirty normal hearing participants were grouped into two based on age: YAG (N = 15) within age range of 18-25 years and OAG (N = 15) within the age range of 65-83 years. Phrases prepared in three speech rates (normal, 35% and 40%) at three different signal-to-noise ratios (SNRs) (quiet, -1 dB SNR and -5 dB SNR) were presented at participant's comfortable level. Results: In each of the rate of speech at each SNR, the perception score was significantly better in deep band modulation (DBM) than UP. Further, perception score of UP from YAG was almost equal to scores of DBM from OAG, in each experimental condition. Conclusion: Older adults can take advantage of envelope enhancement when speech rate is altered and embedded in noise.