Perception of Deep Band Modulated Speech in the Presence of Noise by Elderly Individuals with Hearing Impairment

Background: Deep band modulation (DBM) is an envelope enhancement strategy that enhances temporal modulation and may provide a cue for speech understanding among individuals who suffer from temporal processing deficits. Objective: To investigate the effect of deep band modulation on phrase recognition scores at different signal-to-noise ratios (SNRs) among older adults having hearing loss classified as good and poor performers based on temporal resolution ability. Method: Phrase recognition score was obtained for unprocessed and DBM phrases at three SNRs (4, 5, and - 4 dB signal to noise ratio) in 25 (age range 60 to 82 years, mean age 71.48 years) older adults having bilateral mild to moderately severe sloping sensorineural hearing loss. In addition, the gap detection test was also administered to the study participants. Results: A significant better recognition score was obtained in DBM than the unprocessed phrase. The magnitude of improvement from DBM was not the same in all the participants. Thus, the participants were classified into good and poor performers based on their temporal processing ability. The mean unprocessed and DBM phrase recognition scores in each SNR were higher for good performers than the poor performers. The benefit of deep band modulation was evident for the good performers, especially at high SNR, which was moderately correlated with age and temporal processing ability. Conclusion: The benefit from DBM on recognition score for the good performers is predicted from the temporal resolution abilities and age. However, the benefit is minuscule for the poor performers in noise.