Cochlear Implantation in Kids With Singled-Sided Deafness Improves Speech Perception

By Linda Carroll

November 06, 2020

(Reuters Health) - Most children with single-sided deafness show clinically meaningful improvement in speech perception in both quiet and noisy settings after receiving a cochlear implant, a new study suggests.

In a reanalysis of 12 earlier studies that included a total of 119 children, researchers concluded that the implants also helped with sound localization, according to the report published in JAMA Otolaryngology-Head & Neck Surgery.

"We found that children had better sound localization and better understanding of speech in noisy environments," said study coauthor Dr. Michael S. Cohen, director of the Multidisciplinary Pediatric Hearing Loss Clinic at the Massachusetts Eye and Ear Infirmary and an assistant professor of otolaryngology at the Harvard Medical School in Boston. Moreover, "81% benefited in a quiet environment, which is not typically where you expect them to struggle."

"In the past, families asking what can be done for this have been offered all the traditional accommodations: preferential seating in the classroom and teachers with microphones," Dr. Cohen said. "But this is now another intervention that has been shown to make improvements in quality of life for kids with single-sided hearing loss. It's an important option for kids with this condition."

Dr. Cohen hopes that studies like his will prompt insurance companies to cover the implants. "Although it's approved for this indication by the FDA, it's not universally covered by insurance companies, many saying it's experimental," he said. "It's expensive, and if it's not covered by insurance, most families could not afford it."

To take a closer look at the impact of cochlear implants in children with single-sided deafness, Cohen and his colleagues analyzed studies involving patients younger than 18 with a diagnosis of single-sided deafness that measured at least one of the following outcomes: speech perception, sound localization, device use and patient reported outcomes.

The researchers found 12 studies that met their criteria, six of which were included in a meta-analysis that focused on two outcomes: sound localization and patient-reported outcomes.

All 12 studies were case series with small sample sizes that ranged from three to 23 patients. Eight studies evaluated speech perception in a noisy environment (60 to 70 dB) in a total of 49 children and found that 39 of 49 children experienced improved speech perception in noise after cochlear implantation.

Speech perception in a quiet setting was measured as the proportion of correct responses; speech perception in a noisy environment was measured as decibel signal to noise ratios for speech perception threshold; sound localization was measured in degree of localization error; device use was measured by hours per day of device use; and patient reported outcomes were measured by the speech, spatial and qualities of hearing scale (SSQ).

Six studies, which included 42 children, assessed speech perception in a quiet environment with the normal hearing ear masked and found that 34 kids (81%) had improvement with the implant.

Sound localization was evaluated in six studies. Researchers in those studies used between three and 13 loudspeakers, with various stimuli at 55 to 70 dB. Most children showed improvement in sound localization one to two years after implantation.

Four studies looked at patient reports and compared their responses from before the implantation to those one to three years afterward. Cochlear implants were associated with statistically significant improvements in speech hearing, spatial hearing and hearing quality. Children were more likely to benefit if they had acquired single-side deafness than if they were born with it.

Dr. Maura Cosetti welcomed the new study.

"I think it's great," said Dr. Cosetti, director of the Ear Institute of the New York Eye and Ear Infirmary at Mount Sinai in New York City. "It definitely hits on an area of hot controversy in our current field and it's something I get called about frequently by other ENTs and other doctors, especially since the FDA approved it very recently. There wasn't a lot of guidance and now I think people know it's an option but they're not exactly sure how to counsel patients and families."

The whole concept of cochlear implants for kids with single-sided deafness is new to most people, Dr. Cosetti said. "It's such a departure from what we've done for decades," she explained. "Until recent years, it was assumed that kids with hearing in one ear would be fine. The advice was to put them in the front of the classroom and they'd be fine. But most of these kids had significant if subtle concerns."

One important piece of information from the new study was that time was of the essence, Dr. Cosetti said. Wait too long to do the surgery and the brain might not wire up to the implant properly, she added.

SOURCE: JAMA Otolaryngology-Head & Neck Surgery, online November 5, 2020