By Alexandra Cruz-Mullane, MBS 2019, Geisinger Commonwealth School of Medicine

Mentor: Jennifer Boardman, PhD

Hearing is a sense that many individuals take for granted, yet deafness is one of the most common, debilitating, and invisible disabilities in today’s society. It is an especially personal and important topic to me, as I am deaf. This blog post will discuss how we hear, what are the types of deafness, and current and future treatments. Hopefully, by the end of reading this post, you will have a deeper appreciation of your hearing.

Sound that comes into the outer ear is conducted into the inner ear, where it is eventually transformed into a neural impulse and sent into the brain. If there is a problem along this pathway, one will have one of three hearing impairments. Conductive hearing loss is when sound is not properly sent from the outer ear into the inner ear. Sensorineural hearing loss occurs when sound is not properly transformed into an impulse in the inner ear or not sent to the brain. Mixed hearing loss is a combination of conductive and sensorineural hearing loss. Additionally, one can be born with hearing loss or acquire it later on in life.

Current treatments that exist are hearing aids and cochlear implants. Hearing aids have a wider range of use for more types of deafness, as they amplify sound and are not implanted; the future of hearing aids seems to involve the Internet and machine learning. Cochlear implants (CIs) are a costly, newer implanted device that targets sensorineural deafness by converting sound into an electrical current. CIs take sound and convert it into electrical currents, ultimately transmitting the signal to the brain. The future of CIs seems more aligned with the overall treatment of hearing loss, as they most likely will be moving more towards a fusion of bio-technology. Hearing aids and cochlear implants treat various types of hearing impairments, but nevertheless, are often compared to each other in terms of success in treating deafness.

Future directions of research are looking at hearing impairments from very distinct perspectives: genetic, molecular biologic, microbiologic and immunologic. For example, a geneticist would look to replace the nonfunctional gene with a functioning gene and a molecular biologist would look to regenerate the part of the ear that is not functioning appropriately. Ultimately, most of these approaches use genetics as the basis, but the focus and direction of research are quite different. The results from these experiments and studies are not directly applicable to humans yet. However, they are promising, despite their limitations (side-effects and costliness vs effectiveness).

Not all deaf or hard-of-hearing individuals can benefit from current or future treatments; in this case, assistive technologies would be more helpful. Assistive technologies that are currently available largely include devices to improve audio quality or to transmit information in a visual manner, such as captioning, visual alerting devices (alarm clocks, smoke detectors), text messages, video chats, and captioned telephones. Additionally, there are other assistive technologies that is being developed, and/ or researched; however, their focus is more on individuals who use sign language (SL), rather than the overall hearing-impaired community. Ultimately, it seems that research focuses largely in trying to prevent deafness or eliminate it outright in the future, rather than providing cheaper and more immediate forms of treatment.

Hearing impairments affects a large proportion of the population—both young and old, across all races and ethnicities. Ultimately, hearing impairments are associated with reduced quality of life; according to the World Health Organization, hearing impairments are at the same level as heart disease, depression and Alzheimer’s disease in terms of quality of life. The last thing to consider is the fact that deaf children at eighteen years of age on average read on a third- to fourth-grade level, and this statistic has not changed in fifty years! Between the fact that a huge proportion of the population currently has or will develop this disability, and that it remains one of the most emotionally, academically, socially-isolating disabilities that exists, deafness should be at the forefront in society’s focus.

Deaf individuals struggle more to achieve the same results compared to hearing individuals; individuals with hearing loss remain hyper-alert and vigilant in most situations to be sure everything is okay. For most things that hearing individuals take for granted, deaf people have to use alternatives: text messages or emails instead of phone calls, captioning to watch television, or note-takers to make sure nothing essential is missed in lecture or a meeting. More needs to be done, as most individuals will face some degree of this disability at some point in their life, directly or indirectly.