ARTICLE BY PETER SPENCER DAVIES
People over the age of retirement form the largest cohort of those with hearing loss (although the symptoms will be present in a smaller number of people of a younger age).
This hearing loss, which is a result of the ageing process, has two components: the inner ear and the auditory processing centres of the brain.
Inner ear problems result in loss of loudness and of high frequency components of speech. These can be diagnosed by pure tone audiometric tests and addressed by the fitting of hearing aids.
Ageing effects in the brain result in difficulty with speech discrimination, and with separating speech from background noise. This is called Auditory Processing Disorder (APD) and there is currently no treatment for it, and no agreed test. As a result there are no statistics available on its prevalence. Anecdotal evidence suggests that it varies in severity and is widespread in this age group.
Background noise may include music and chatter in networking gatherings or restaurants.
The difficulties of background noise are compounded by reverberation.
Reverberation is the acoustical decay of sound (how long it takes a sound to disappear) and it is recognised as having a negative impact on speech intelligibility, especially for hearing aid users.
The overlapping and smearing of speech sounds caused by reverberation makes it hard for listeners to distinguish words, especially listeners who are hearing aid users and/or who have APD.
Reverberation is a common reason for inability to hear and for reduced access, enjoyment and participation in meetings, informal gatherings, lectures etc.
APD is recognised in a small proportion of children, and the importance of being able to hear in classrooms has been recognised by the UK government. There is legislation for building standards that address the acoustics of classrooms by specifying acceptable levels of reverberation.
There is no equivalent for meeting rooms and lecture theatres etc., and as a result many people who are hearing aid users and/or who have age-related APD are denied hearing access because of unregulated reverberation. They usually stop attending meetings and social gatherings, and this contributes to loneliness and social isolation. However, venues can be fitted with sound absorbing acoustic panels to reduce reverberation to an acceptable level.
There are three things that exacerbate the problem for people with APD:
- Lack of appreciation of the serious impact reverberation has on speech intelligibility and listening experiences.
- Lack of understanding of hearing difficulty due to APD, with no data to evidence the numbers who experience it
- Typically those whose hearing is affected by APD stop attending an activity, rather than seek solutions for the problem that prevents their participation.
How do I feel this be addressed?
- Request the Scottish government to revise the building regulations, to require all public buildings and other meeting places to comply with reverberation standards equivalent to those in place for schools.
- Require owners of public and other meeting places to have an acoustic audit followed by application of the necessary remedial measures for reverberation reduction.
- Request the Scottish Government to consider a grant-aided scheme to assist with initial costs of acoustic assessment and treatment.
- Liaise with members of the Audiology profession to devise a test, even if imperfect, so that that data can be obtained on the true prevalence of APD.