Tinnitus & Hidden Hearing Loss
The symptom of tinnitus is usually associated with problems of the ear such as a hearing loss. Even when there is no measurable hearing loss found from a conventional audiometric hearing test, we do also need to be aware of other forms of hearing loss that can be quite hidden.
For example, in most cases we usually only test hearing up to 8KHz but we start off life with hearing in the range from 20Hz to 20KHz. As we get older, we lose the ability to hear some of the highest frequencies. This means that at age 10 we might be able to hear bats echolocation (20KHz) by the age of 20 this has been lost to us. The rate and degree of drop off after 8KHz is often hidden to us but the brain knows it is no longer hearing these sounds as well.
Approximately 80% of tinnitus suffering stems from a hearing condition. And it's also worth noting that 8 out of 10 people with both hearing loss and tinnitus find that their tinnitus improves or completely disappears immediately when the hearing loss is corrected with a hearing aid.
In the UK, only a fraction of audiologists can call themselves tinnitus specialists or experts. Tinnitus Centres aims to bring these audiologists together on one website to make it easy for tinnitus sufferers to find the right help locally to them.
Because audiologists are the only people who can fit hearing aids in the UK and have access to specialising in tinnitus, they are in the unique position of being able to provide the most help to people with tinnitus.
Most, but not all! But their specialist knowledge will enable them to refer a patient they can't help to the right professional.
Where else can hearing loss be hiding?
We can also develop a weaker connection from the inner ear to the nerve of hearing going up to the brain. This might not show up as a difficulty detecting sound such as in a normal hearing test but can be seen as an unusually greater difficulty understanding speech in noise.
Audiologists will often perform a ‘Speech in Noise’ test as part of their battery of assessments and the results of these can sometimes be quite surprising. Not infrequently, the poorer hearing ear performs better in the speech in noise test. This can help reveal underlying subtle damage that can help us to select the best hearing system for our patients. So it is possible to have a 'Signal to Noise' ratio hearing loss (SNRloss) even where the simple detection test of Pure Tone Audiometry seems normal.
There has been a lot of research recently on what is called ‘Listening effort’. This is the amount of concentration and energy someone with a hearing loss has to put in to understand speech compared to normal hearing subjects.
Interestingly, not only does hearing loss result in fatigue, but the act of straining to listen also seems to make things worse. When we strain we are actually progressively weakening our auditory filters.
This might be helpful to catch some conversation but as the filters widen and fatigue sets in we can be overwhelmed by noise. It is often reported by patients that because of the fatigue and widened filters by the end of the evening, their tinnitus can be significantly worse.
Over the last 2-3 years, hearing aid manufacturers have been putting a great deal more effort in off-loading some of this processing effort onto their hearing aid chips. Systems such as Oticon’s ‘Brainhearing’ or Resounds’ ‘Surround Sound’ attempt to manage the noise first before sending speech onto the wearer, helping to reduce this fatigue.
Deciding which combination of hearing aid, speaker and ear fitting is right for you is a highly complex task. A Tinnitus Centres expert understands this and will ensure that every patient's individual needs are met with the hearing systems they select.