When it comes to treating tinnitus, hearing aids are a popular and effective management strategy amongst audiologists, dating back to the late 1940s.
In fact, asides from tinnitus-specific cognitive behavioural therapy (a good choice for those with severely distressing tinnitus), hearing aids are considered to be one of the safest and most effective management options for tinnitus. A relatively large body of favourable clinical studies and evidence exists to support their efficacy. They are also recommended as part of the British Society of Audiology national clinical guidelines and indeed by the British Tinnitus Association. At this point one should point out the obvious; the tinnitus "sufferer" should have a clinically suitable hearing loss on which to prescribe a hearing aid. Luckily, most individuals with tinnitus will also have some co-morbid degree of underlying hearing loss which qualifies for hearing aid support (plenty of population studies exist to back this up). Interestingly though, the degree of hearing loss isn't always great and may even extend in to higher frequency regions beyond the range of conventional hearing tests (i.e > 8kHz). Also one should point out that the presence of tinnitus does not automatically indicate the presence of a hearing loss (you can place me in the category of tinnitus and "normal" hearing). So for the purposes of this article and with prevalence statistics on our side, lets assume that you have tinnitus AND you have an aidable hearing loss.
What are the possible benefits of trying hearing aids and what are the supposed mechanisms at play?
Well the former is easier to answer than the latter given that the objective quantification of tinnitus on a single subject level still isn't yet a possibility (excluding somato-sound tinnitus relating to muscular or vascular bodily activity). Here we are talking about the more common "neural noise" phantom sound type tinnitus that most people have.
Subjective reported benefits of hearing aid use for individuals with tinnitus include: a reduction in tinnitus awareness, a reduction in tinnitus loudness and related-distress, an improvement in hearing and speech understanding, an improvement in concentration and in quality of life and an overall sense of relief from their tinnitus. Hearing aids can also offer the user a sense of control over their tinnitus, which is a powerful thing.
And what about the mechanisms behind it all? Well, given that tinnitus is still a somewhat enigmatic condition, it is difficult to pinpoint exactly the neurophysiological reason(s) for such benefits. Partly because experimentally, it is difficult (arguably still not even possible) to reliably measure tinnitus-specific neurophysiological activities in humans. In simple terms we cannot perform a quick objective test and measure / quantify someone's tinnitus. We must also not forget that each individual may have a different type of tinnitus and may experience a different benefit - heterogeneity is likely.
Several hypotheses for hearing aid benefit on tinnitus perception have been reported in the literature. These include: an increase in hearing ability may suppress or alter tinnitus related brain activity. Sounds from the hearing aids may offer a distraction or mask the tinnitus. A general improvement in one's hearing and communication ability positively impacts quality of life and thus the tinnitus severity is reduced. Whilst patient's may offer their subjective opinion on this, it is difficult to know for sure and again, we cannot assume a single mechanism is at play. (Here you start to get a flavour for some of the difficulties that tinnitus researchers face when trying to design such studies).
In conclusion, given the weight of favourable evidence supporting the use of hearing aids as part of a tinnitus management strategy (caveat: assuming there is an "aidable degree of hearing loss"), patients should feel confident to try them out if they are experiencing bothersome tinnitus. In the case of existing hearing aid users, one should also consider the adoption of additional tinnitus sound generation capabilities which most if not all newly emerging hearing aid technologies are starting to incorporate.
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