Chronic conductive hearing loss has been linked to speech recognition deficits, according to the results of a new study published in Ear and Hearing. The study suggests neural deficits and increased difficulties hearing in noisy environments may result when infections or other conditions that chronically affect the middle ear are not properly treated.
Lead author Stéphane F. Maison, PhD, AuD, a researcher at Eaton-Peabody Laboratories at Massachusetts Eye and Ear and an assistant professor of otolaryngology head–neck surgery at Harvard Medical School in Boston, said, “Our results suggest that chronic sound deprivation can lead to speech recognition difficulties consistent with cochlear synaptopathy, also known as hidden hearing loss. Accordingly, clinicians should consider providing amplification in the management of unilateral conductive hearing loss.”
The researchers retrospectively reviewed the hearing profiles of 240 patients who visited the audiology department at Mass. Eye and Ear with either an acute or chronic conductive hearing loss but with normal sensorineural function on hearing tests. The investigators found that patients with a longstanding conductive hearing impairment of a moderate to moderately severe degree had lower speech-recognition scores on the affected side than the healthy side, even when the speech was loud enough to be clearly audible.
“People with hearing loss in one ear are often reluctant to engage in rehabilitation or treatment as they still can rely on the better ear. Our study suggests that, in absence of treatment, speech perception may worsen in time,” said Dr. Maison. “If what we have observed in mice is applicable to humans, there is a possibility that unilateral sound deprivation may affect the good ear as well.”
The authors concluded that the findings were especially important because children with asymmetric hearing loss have higher rates of academic, social, and behavioral difficulties.