Picture of of eeg test results.

How often have has this happened? You ask someone to speak up because you didn’t hear them? They nearly yell to be heard. But you still couldn’t understand what they said.

It’s frustrating. It often happens without notice. It can agitate both the hearing aid wearer and the person trying to be understood.

Scientists know why this happens, and they think they may soon have an answer to this problem.

Why Hearing and Understanding Aren’t The Same Things

There is currently no cure for permanent hearing loss. Called sensorineural hearing loss, this form of hearing loss occurs when the inner ear is damaged. The tiny hairs that pick up sound die when exposed to loud sounds or other causes. Once they die, they don’t grow back.

Permanent hearing loss results.

These tiny hairs respond to different frequencies (pitches) of sound. The ones that respond to high frequencies tend to die first because high frequency is more damaging at a lower volume.

Hearing aids work by collecting sound more efficiently from the environment. They then pass the sound waves over these tiny hair cells in strategic ways to get the best hearing experience possible based upon the level of hearing damage.

If certain hair cells that pick up certain frequencies are missing, then you don’t hear that sound. The hearing aid can’t change that. If the hair cell is damaged but not dead, then the sound may seem distorted.

Now let’s consider how this hearing loss works with a human voice.

A man’s voice is between around 100 hertz (Hz) and 8KHz. A woman’s is between 350 Hz to 17KHz. Speaking frequencies tend to be in the lower range for both men and women. But this demonstrates the wide range of frequencies that human voices can achieve in speaking and singing.

When you speak, you don’t speak in one frequency. Even a person with a very “monotone” voice doesn’t do that. You speak in multiple frequencies. If someone is speaking to you across multiple frequencies and you don’t have the little hair cells to pick up certain frequencies, you hear a gap in an otherwise understandable statement.

The more dead hair cells in your inner ear, the more gaps you experience.

Your brain can amazingly fill in many of these gaps through the mighty power of “deduction.” But this can cause misunderstanding when you assume wrong.

How Mind Reading Technology May Solve This

Scientists have been running studies using an EEG brain cap. You’ve probably seen those in movies or on the Internet.

A participant wears it on his or her head. It then measures the brain waves and can determine what part of the brain responds to certain sounds.

This brain scan can tell not only if you heard sound; it can also look at brain activity to determine if you understood what you heard.

Researchers are hopeful that this technology will help them develop medical devices that can:

  • Determine if a person in a coma can understand them. This could completely change how we interact with and treat those in a vegetative state.
  • Diagnose hearing challenges in children at earlier ages. Earlier treatment could reduce speech impediments and learning challenges that result from hearing disorders that normally go undiagnosed until a child begins talking.
  • Help students with learning disabilities. Children could be tested to determine their level of understanding so that more effective learning plans can be designed.
  • Develop hearing aids that can interact directly with the brain, bypassing the damaged hair cells. Or the hearing aids of the near future may use machine learning to improve your hearing experience the more you wear your aid. Machine learning means that the hearing aid could learn what you can and can’t understand. It could then adapt or change the sound to different frequencies to improve understanding. This would revolutionize how you hear with assistive devices.

We look forward to seeing how this research and technology develops over time.