There are several ways in which a stroke or a transient ischaemic attack (TIA) can impact your hearing:
Sudden hearing loss
Hearing distortion (tonal)
Speech perception difficulties, especially in difficult hearing conditions
Hypersensitivity to sound
Tinnitus and other phantom auditory disturbances
Stroke and TIA cause damage by either blood leaking into brain tissue, or reducing oxygen supply to the tissue. There can be areas of tissue that die, but also surrounding areas which cause symptoms that recover/change with time.
Hearing loss is a common effect of stroke/TIA, such that medics should check for this when assessing sudden hearing loss cases. Audiologists who are called upon for advice with sudden hearing loss should ask if the patient has any other symptoms and impress on them the need to seek fast medical attention, especially when vertigo is also present. A hearing test copy and covering letter detailing changes/concerning symptoms can be provided. More senior audiologists will be aware of at least one case where a patient has been told over the phone to get earwax removal, only to develop serious medical/hearing symptoms!
Although the inner ear (cochlea) is well protected within the skull, it is sensitive to oxygen deprivation and nerve damage. The hearing nervous system, auditory cortexes, and their connections to other areas such as speech are more spread out. Any of these could potentially be damaged, and are often overlooked while the patient is receiving medical attention. Fortunately, as the patient has two sides to the brain, if only one side is damaged the symptoms can be subtle and compensated for. The negative side of this is that more advanced audiological testing is needed to prove damage/symptoms.
A drop in hearing sensitivity will show on a hearing test and can be remedied by reprogramming existing aids. Auditory perception and other central brain functions can be much more difficult to treat and counsel for. The importance of helping your patient recover can’t be overstated. Ask probing questions. If they are reporting the rarer symptoms of abnormal perception/distortion, new difficulty hearing speech in noise, changed tinnitus/hyperacusis etc, take note of these and offer strategies to help.
Speech in noise difficulty can be retested with e.g. QuickSIN. Remote microphones or auditory training may help. If retrocochlear lesions are suspected, you may need to refer onwards for greater support.
Tinnitus and hyperacusis can be helped with sound strategies, volume controls, a program that reduces high frequency gain. Again, patients may benefit from referrals for counselling or cognitive behavioural therapy if it is out of the audiologist’s scope of practice.
Changes in perception of tone are rarer (though may be underreported), but can be distressing and interfere with enjoyment of life and music.
It can take months for recovery from stroke, so patients should be counselled that their symptoms might improve. Options like a comfort/directional program for hyperacusis may be preferable to a more permanent lowering of volume, and patients should be followed up or invited back if they need further input. Training on how to use AI-based programs (e.g. Widex My Sound) may also be useful, so the patient can adjust their aids to their needs in the moment. AI is an exciting technology that allow the patient to directly compare multiple different settings in God their own time/environment and save for future use. In the case of some rarer post-stroke dysfunction this could be invaluable.
Sources/further reading
Lechevalier, B., Lambert, J., Moreau, S., Platel, H. and Viader, F., 2007. Auditory disorders related to strokes. The behavioral and cognitive neurology of stroke, pp.348-368.
Zhong, Y., Li, H., Liu, G., Liu, J., Mo, J.J., Zhao, X. and Ju, Y., 2023. Early detection of stroke at the sudden sensorineural hearing loss stage. Frontiers in Neurology, 14, p.1293102.
Wong, E.C., Wong, M.N., Chen, S. and Lin, J.Y., 2024. Pitch variation skills in Cantonese speakers with apraxia of speech after stroke: Preliminary findings of acoustic analyses. Journal of Speech, Language, and Hearing Research, 67(1), pp.1-33.
Haley, K.L., Jacks, A., Richardson, J.D. and Wambaugh, J.L., 2017. Perceptually salient sound distortions and apraxia of speech: A performance continuum. American Journal of Speech-Language Pathology, 26(2S), pp.631-640.
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