Hearing and Cognition

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How does hearing work in the ear?

The brain and ears work in unison to detect noise and convert it into useful sounds. Let’s look at these processes separately, starting with the ear.

Overview

  1. The pinna collects the sound waves
  2.  The sound waves are directed by the ear canal to the eardrum
  3. The eardrum is hit by the sound waves and it vibrates
  4. The vibrations are magnified by the ear bones and are transmitted to the cochlea
  5. The cochlea changes these vibrations into electrical nerve impulses
  6. These impulses are sent by the auditory nerves to the brain
  7. The brain interprets these nerve impulses as sound
Anatomy of the Ear
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The Inner Ear

The Inner Ear
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  1. Determining what a sound is begins at a flat sheet of tissue inside the cochlea called the basilar membrane
  2. This system detects the frequencies, or tones, of incoming sound
  3. The membrane is flexible, and vibrates when sound hits it, but it doesn’t vibrate evenly all over
  4. One end of the basilar membrane vibrates most at low frequency tones and the other end of the membrane vibrates most at higher frequencies
  5. Tiny hair cells cover the basilar membrane that vibrate when a sound hits it
  6. Smaller, stiff hair cells help the high notes and longer, floppier hair cells detect the low notes

How does hearing work in the brain?

How can I improve my hearing and auditory processing?

In addition to using BrainHQ, here are some great ways to fine tune hearing skills.

When listening to your favorite music, try to pick out the individual instruments, voices, notes and melodies. This sound isolation technique makes your brain work harder when listening and can improve your auditory processing skills! 

You could also close your eyes at various times during the day and try to identify as many different sounds as you can like a bird, the wind, traffic, children playing, Try listening to these for as long as you can to strengthen your concentration and conversation abilities.

Wherever possible, try and avoid any loud noises. If you must be around a high level of noise, such as a concert or a noisy work environment, wearing some form of ear protection and distance yourself as much as possible from the source of the noise is recommended. 

Exposure to loud noise, whether consistently over time or in one sudden impulse, is a major cause of sensorineural hearing loss. An abnormally loud burst of noise can physically perforate the eardrum whilst more consistent exposure can cause long-term, irreversible damage to the sensitive inner ear hair cells.

You already know that exercise increases blood flow to the brain but it also increases blood flow to the ears. This helps to maintain the health of the inner ear hair cells that cannot be helped or regenerated once damaged.

You will notice that there is a lot of recurring themes with exercise, diet and the outdoors featuring as suggestions for lots of different neurological improvements. This may be the reason you need to go for that walk or skip an afternoon biscuit.

A recent study showed that smoking almost doubles your chance of hearing loss. According to the study, nicotine consumption also leads to tinnitus (ringing in the ears), and second-hand smoke from your partner can cause hearing loss in you, even if you’ve never smoked a cigarette in your life.

The thought of not being able to appreciate your favourite band or musician might be enough of an incentive for you to stub it out, for good!

Don’t forget that you can get your hearing checked by an audiologist who may recommend regular check ups to review the progress you’re making with improving your hearing and auditory skills.

The Cochlear Ear Implant - Brain Plasticity at Work

Earlier in the lesson we learned about the important role that the cochlea has within the inner ear to help convert sounds into electrical signals that the brain can interpret. Some people with severe to profound hearing loss can restore their hearing with the aid of a Cochlear Ear Implant.

Professor Merzenich is one of five scientists credited with developing this device, having conducted its first clinical trials and paving the way for its commercialisation in the late 1980s by Advanced Bionics. This short video describes how Professor Merzenich harnessed the power of neuroplasticity to create this medical device that has now transformed the health and happiness of over 320,000 people across the globe.