Need of speech-in-noise testing to assess listening difficulties in older adults

Objective: To assess the need of including speech-in-noise tests in the audiological test battery in older adults and the key factors that affect performance in these tests. Older adults complain significantly more than other age groups regarding difficulties in hearing speech in noise, even in the presence of a normal audiogram. Hearing speech in noise is a very complex function underpinned by high-level, cognitive and analytic processing along with low-level sensory processing. Study design: The design reflected an overview of the effect of aging in the auditory system and the acoustic and cognitive resources required for hearing speech in noise. In addition, a review of key clinical studies of speech-in-noise tests was conducted in older adults. Results: Age affects the peripheral and central auditory system but also the entire brain at a structural, functional and neurochemical level. Listening to speech in noise requires complex and multimodal processing in auditory, linguistic, cognitive and other domains via multiple brain interconnections that are not yet fully understood. There are several different theories and models proposed to explain age related declines in speech-in-noise performance. Listeners may give different scores in speech-in-noise tests depending on the parameters of these tests, e.g. type of speech stimulus (words vs. sentences) and masker (noise, multi-talker babbler). Speech recognition in noise depends on the degree of direct interaction of the target and masker at the cochlear level (energetic masking) and on how well speech can be dissociated from the masker (informational masking). Studies show more pronounced effects of informational masking and of lexical interference in older adults, who also show poorer use of auditory sensory type cues, and require greater listening effort in order to perform speech-in-noise tasks. Conclusion: Assessing older adults with pure tone audiometry only and addressing these difficulties with hearing amplification may not be enough to address older adults’ hearing needs, as this approach does not take into account the higher level impairments contributing to hearing and listening problems. Careful audiological assessment with appropriately chosen speech-in-noise tests, together with audiometry and potentially additional tests, are thus required in order to identify and characterize hearing difficulties in older adults, in order to inform their management plan.