Hearing impairment affects around 1.5 billion individuals worldwide (World Health Organization), and there is growing evidence that this could increase the risk of dementia. A major component of hearing impairment is difficulty hearing speech in noisy environments (speech-in-noise hearing impairment). This can have a large impact on the day-to-day functioning of affected individuals who can struggle to follow conversations or hear announcements in noisy environments. However, until now it was unclear whether difficulty hearing speech-in-noise was associated with developing dementia.
This has now been robustly investigated in a new study led by the University of Oxford’s Nuffield Department of Population Health (NDPH) published today in Alzheimer's & Dementia: The Journal of the Alzheimer's Association. The study involved over 82,000 women and men aged 60 years or older from UK Biobank. At the beginning of the study, participants were asked to identify spoken numbers against a background of white noise and based on this test were grouped by the researchers into normal, insufficient and poor speech-in-noise hearing.