Effect of rate-alteration on speech perception in noise in older adults with normal hearing and hearing impairment

The purpose of this study was to evaluate the effect of using slow and fast speaking rates in competing noise on older adults with normal hearing (NH) and those with hearing impairment (HI).

Thirty-four older adults (56-85 years) were grouped based on hearing ability-NH (N = 15) and HI (N = 19). Rate-altered Quick Speech-in-Noise Test (QuickSIN; Etymotic Research, 2001) stimuli were presented at 3 speech rates (slow, average, and fast), and the signal-to-noise ratio (SNR) loss was calculated for each.

The older participants with HI had significantly higher SNR loss than the NH participants at all 3 speech rates. The NH participants showed improved speech perception in noise when a slow rate of speech was used. This benefit was not observed for the participants with HI. Both groups performed poorly with the fastest speech rate.

Results suggest that older adults with HI who are not wearing hearing aids are not able to take advantage of additional processing time afforded by the use of slow speaking rates when speech (70-75 dB HL) is presented in competing noise. Additionally, the use of a fast speaking rate significantly reduces an individual's ability to perceive speech in noise, regardless of hearing status. Decreasing from a fast speaking rate to an average rate is beneficial and should be recommended by audiologists to increase the likelihood of older adults understanding speech in noise.