Second-Time Hearing Handicap

Donna experienced a progressive hearing loss, which began in her early 20s and became profound in her mid 30s. She sought a cochlear implant at a point when she could no longer understand speech without speechreading and feared she would no longer be able to do her passionate work in public affairs. Her cochlear implant provided immediate benefit and improved over time with listening experience and advances in sound processors. While she still has some difficulty hearing in noise, she no longer feels significantly handicapped as she did prior to getting the implant.

Feng lost his hearing due to ototoxic drugs at age 21. The hearing loss led to depression and also significant weight loss. He received a cochlear implant, which he hoped would restore his hearing. Fortunately, not only did he become a star user, but he also regained his weight and landed a dream job. However, Feng noted that while the implant allowed him to understand most speech in quiet, he had difficulty listening in noise and could not carry on a conversation for an extended time because that would tire him out. Feng discovered that he still suffers from “second-time hearing handicap.”

The cochlear implant, as the most successful neural prosthesis, has restored functional hearing for over one million people worldwide. ¹ On average, the implant improved sentence recognition from the pre-surgical performance of 24% correct to the post-surgical performance of 77%, but the individual variability is large. ² Donna and Feng represent the range of the second-time hearing handicap in actual cochlear implant users. Unlike the first-time hearing handicap, which, made both Feng and Donna rely on lipreading only, the second-time hearing handicap is less apparent but real. For example, in a realistic situation where two people talk at the same loudness and at the same time, a normal-hearing listener can switch attention between them and understand each perfectly. ³ In contrast, an average implant user might not understand much speech in the presence of the two simultaneous talkers, even though she or he could understand most if only one talker was present. A second example is that individuals with severe or greater hearing loss would need more listening effort than a normal-hearing person to understand speech, especially in noise. ⁴ This increased listening effort may more likely tire out a cochlear implant user than a normal-hearing listener.

In theory, the degree of the second-time hearing handicap is the difference between aided and normal performance, but in reality, it is difficult to measure. One reason for the difficulty is that cochlear implants restore audibility but do not restore normal hearing. ⁵ Another reason is that the second-time hearing handicap is likely central, reflecting brain changes in response to the peripheral hearing loss. These changes may produce a wide range of abnormalities from impaired suprathreshold auditory processing to increased cognitive loads and even tinnitus or hyperacusis. The second-time hearing handicap may reflect several clinical symptoms such as hidden hearing loss, central auditory processing disorders, or even cognitive impairment. At present, none of the current hearing devices corrects these abnormalities in individuals with hearing loss.

It is important for both the patients and clinicians to be aware of the second-time hearing handicap so that they have proper expectation of the hearing device outcome. They should also pay equal attention to rehabilitation in terms of acclimatizing to the device and individualizing learning and training protocols.

The second-time hearing handicap is also applicable to hearing aid users because they often complain about hearing in noise difficulty. ⁶ Like cochlear implants, current hearing aids do not restore normal hearing either. ^7,8 New technologies from automatic captioning to artificial intelligence are being developed to compensate for not only audibility loss but also suprathreshold processing impairment. ^9,10

Feng, who recently received a contralateral implant, said that he can now handle more noise and much longer conversations than before. Donna has had her implant for nearly 30 years and notes that while she doesn’t have normal hearing, her life has been changed so dramatically that the disability she experienced prior to getting a cochlear implant is largely diminished.