Although it’s unclear exactly why people with diabetes experience hearing loss, it’s thought that the main reason is related to the blood vessels in your ear.
Diabetes causes you to experience high blood sugar (glucose) levels as the lack of insulin means the sugar can’t enter your body’s cells.
Prolonged levels of high blood sugar can:
Reduce your body’s circulation of blood and oxygen to the nerves and blood vessels in your inner ear
Damage the protective layer of hair that covers your nerves inside your ear. These hairs are responsible for transmitting impulses from the cochlea to the hearing centre of the brain
Block some sensory receptors in your ear
These ultimately damage the nerves and blood vessels of your ear, which then affect your ability to hear.
Nerve damage is a well-known complication of diabetes, so this applies to the auditory nerves in your ear too.
Your hearing can also be affected by periods of low blood sugar. Your ear contains a special fluid around the cochlea, which is vital for it to function. Low blood sugar levels cause a chemical imbalance in this fluid, thereby changing the way your ear processes sounds.