Hearing loss or hearing impairment is a reduced ability to hear sounds or speech. This may be due to a problem with the ears, nerves, or the part of the brain that processes sound. (Read more about how hearing works here!)
Hearing loss may be temporary. You may experience temporary hearing loss when you have an ear infection or after you go to a loud concert.
Hearing loss may also be permanent. People can be born with hearing loss or can acquire it later in life. Hearing loss comes in different degrees and types, both of which affect how easy or hard it is to hear different things.
Types of hearing loss:
People may have hearing loss in one ear (unilateral) or both ears (bilateral).
Hearing loss from damage to the outer ear or middle ear is called conductive hearing loss. Hearing loss from damage to the cochlea, auditory nerve, or brain is called sensorineural. Sometimes people have a mix of the two, which is called mixed hearing loss.
Degrees of hearing loss:
Hearing loss is measured in decibels (dB). Higher decibels of hearing loss mean that sounds need to be louder for the person to hear them. For example, 25 decibels of hearing loss means that sounds need to be at 25 decibels (about the same as leaves rustling) to be heard. 110 decibels of hearing loss means that sounds need to be as loud as a rock concert to be heard! This often varies for different pitches; someone might have 60 decibels of hearing loss for high-pitched sounds and 30 decibels of hearing loss for low-pitched sounds.
Erin is a Ph.D. student in the Bergelson lab at Duke University, where she studies how young children who are Deaf or blind learn language.