Love Your Ears

There's a ton of discussion about vocal health in the singing world, and how to keep our voices healthy over a (hopefully) long career. Another aspect of health that I don't think we discuss enough is hearing health.

Your ears are an essential part of your teaching tool kit. The ability to hear a singer and know what is happening physiologically is an indispensable part of your work. But what happens when your ears aren't working as well as they used to? Or what if you have a student with hearing loss? Those are really big questions, and there's a whole lot to discuss about them, but let's get started by defining what hearing loss is, and some important ways to prevent it. Unlike your voice, damage to your hearing is very often permanent, and avoiding injury is the only way to keep your hearing pristine for as long as possible.

The mechanism of hearing

Your ears are truly a wonder of mechanical and neurological function. I could spend time explaining how it works, but instead, I'll point you to this excellent video that I've used in classrooms for years about how the ear works. In less than seven minutes, you'll get a really good overview of the mechanics of hearing, called auditory transduction.

Types of hearing loss

There are three main types of hearing loss: sensorineural hearing loss, conductive hearing loss, and a mixed hearing loss that has some of both.

Sensorineural hearing loss, also sometimes called noise-induced hearing loss, is the most common type and what we generally encounter as we age. However, it can happen at any point during a person's life, either suddenly or gradually over time, though gradual hearing loss is most common.

As illustrated in the above video, hair cells toward the opening of the cochlea pick up higher frequencies, and lower frequencies are picked up by hair cells higher up in the cochlea. Like with all things physics, as energy moves through a medium, in this case the lymphatic fluid in the cochlea, it loses energy. So the highest sound pressure energy is felt by the hair cells at the beginning of the cochlea, compared to those farther along the fluid trail. Now, it's a small difference, but it is important nonetheless. Because those higher frequencies are generally for unvoiced consonant sounds, with voiced consonants being a little lower in frequency, when those high frequency hair cells are damaged, they are less able to pick up those consonant sounds. This photo shows microscopic photos of normal cochlear hair cells and cells that have been damaged.

The damage to high frequency hair cells makes speech unintelligible, and most of the time when folks are having trouble discerning speech because of hearing loss, the vowel sounds (lower in frequency) are still clear enough, but the higher frequency sounds are missing. So it's not so much that folks can't hear, it's that they can't understand. For an example of what hearing loss is like, this video from the Hearing Health Centre in the UK is helpful:

Conductive hearing loss is less common, but can be just as impactful. A person with a conductive hearing loss has had damage to the actual structures in the ear somewhere along the pathway. Sometimes this type of hearing loss is congenital, and sometimes it occurs from injury.