Individuals with both types I and II diabetes experience hearing loss at a greater rate than individuals who do not have diabetes.
In fact, diabetes is the most common medically based cause of hearing loss.
The following difficulties are strongly associated with diabetes:
- Overall poorer hearing than those without diabetes. Why?
Diabetes creates hearing loss by reducing blood flow to the cochlea, which creates irreversible micro and macro damage to the stria vasularis and basilar membrane. Damage to these structures causes high-frequency hearing loss where consonants occur, particularly when the diabetes is poorly controlled. However, diabetes may result in hearing loss that affects all frequencies of speech.
High-frequency hearing loss reduces one’s ability to both hear and understand speech. In fact, one of the telltale characteristics of high-frequency hearing loss is the reduced ability to understand speech when listening in background noise.
- Overall poorer ability to understand speech in background noise. Why?
Diabetes causes damage to auditory areas at the brainstem as well as at the auditory cortex. This skill can by evaluated by the audiologist using a speech-in-noise test. An individual’s score on this test provides important information to the clinician, particularly when it comes to making recommendations for management of the hearing loss.
- In addition to auditory impairment, hypoglycemia also has significant negative effects on memory and general processing of sensory information, both visual and auditory. Cognitive decline is also associated with hypoglycemia.
Hearing loss and reduced understanding of speech occurs more frequently in the diabetic patient. Since hearing loss and diabetes are both associated with impairment of speech understanding as well as associated with cognitive decline, it is important that those with diabetes receive annual hearing evaluations by an audiologist. The hearing test should include both general degree of hearing loss and speech-in-noise assessment. Additionally, otoacoustic emission testing will help to identify early micromechanical changes to the cochlea, which will not necessarily show up on a standard hearing test.
Finally, regardless of origin of damage to the auditory system, diabetes or otherwise, the importance of management of the sensory hearing loss should not go overlooked. The first step in understanding your hearing loss is a comprehensive evaluation of hearing and speech processing by an audiologist.
— Sharon Macner, Au.D.
Sanju, HK, Kumar, P. Annual audiologic evaluations should be mandatory for patients with diabetes. Hearing Review. 2016; 23(1): 14-15.