Aging and Speech Perception
Jin, Liu, and Sladen reported on the 1988 Working Group on Speech Understanding and Aging Committee on Hearing, Bioacoustics and Biomechanics (CHABA), which stated three likely factors for age-related listening problems: (1) changes in the peripheral auditory system, (2) changes in central auditory processing, and (3) changes in cognitive performance. These three factors may present in isolation or in tandem in any combination and the severity of each (of the three factors) is highly variable. Previous publications have consistently demonstrated that for older adults with normal and nearly normal hearing, speech understanding in noise is problematic. Dubno and colleagues (2002) reported people with reduced temporal resolution (due to aging or hearing loss) demonstrate poor speech recognition in temporally modulated noise. It has been reported that deficient temporal processing may be a major factor associated with age-related speech in noise difficulties.
Jin, Liu, and Sladen note that “regardless of the state of their hearing, elderly listeners are often frustrated at not being able to understand speech in background noise….” Therefore, they evaluated two groups of people with normal hearing (11 younger and 12 older) and two groups of people with cochlear implants (7 younger and 6 older) to investigate the effect of aging on temporal processing and the effect of aging on speech perception in noise. They reasoned that if the “aging effect” occurs in peripheral and cognitive processing, it (i.e., the aging effect) should be apparent in normal hearing people and in people with cochlear implants.
Jin, Liu, and Sladen report that “within normal hearing (NH) and cochlear implant (CI) groups, older listeners performed more poorly than younger listeners on tasks of sentence recognition in noise and temporal modulation detection at low modulation rates….” They report age-related reductions in speech understanding are “likely multi-factorial, including peripheral and central factors….” They note the trend reported (earlier) implies that for older people, reduced speech recognition in noise was most likely secondary to age-related changes “in the higher levels of auditory processing rather than in the cochlea….” Additionally they note that age-related changes often include reduced selective attention (a lesser ability to ignore noise while focusing on target speech sounds) and may include reduced executive function, perhaps related to reduced pre-frontal function. They note that “on the basis of these findings, one could speculate that older listeners are less effective at distinguishing speech from complex noise…(due to a)…reduced ability to process temporal varying information….”
For More Information, References, and Recommendations
Beck DL, Flexer C. (2011) Listening Is Where Hearing Meets Brain in Children and Adults. Hearing Review. February:30-35
Dubno JR, Horwitz AR, Ahlstrom JB. (2002) Benefit of Modulated Maskers for Speech recognition by Younger and Older Adults with Normal Hearing. Journal of the Acoustical Society of America. 97(1):2897-2907.
Jin SH, Liu C, Sladen DP. (2014) The Effects of Aging on Speech Perception in Noise: Comparison between Normal Hearing and Cochlear-Implant Listeners. JAAA. 26:656-665.