How Do We Hear Voices in a Crowd?

How Do We Hear Voices in a Crowd?

Peter Lucier, HIS

Many people with hearing loss have experienced a similar phenomenon: when talking with one person face-to-face at home or in an otherwise quiet environment, they are able to understand what is said. Although the volume of speech might appear to be low, words can be understood to some degree. However, the entire situation can be turned on its head when there are multiple voices in the same place. What was once easily discerned as speech is transformed into a haze of indecipherable noise. Although the person may be speaking in close enough range, it is as if the combination of multiple voices in a place merges into a single voice speaking an unknown language.


Looking to the Ear for Inspiration

Although incredible advances have been made in hearing aid technology, the ability to differentiate voices in a crowd has posed a persistent challenge to device developers and inventors. Researchers at MIT have been taking a closer look at one part of the inner ear that seems to be responsible for fine-tuned sound discrimination.

The tectorial membrane is a gel tinier than a human hair, and it is tasked with stimulating the sensory receptors of the inner ear. These transmissions are then communicated to the brain via the auditory nerve, and the specific electrical information contained in these signals must be very precise to differentiate space and slight timbral differences between voices. Varying pitch and intensity are difficult to pick apart from one another, and this gel relies on pores of varying sizes to tell one sound from another.

The size of the pores in this tectorial membrane turns out to be crucial to the process of sound discrimination. A study of this membrane looked at mice as an exemplar of the ability to differentiate sound. The pores on their tectorial membranes are only 40 nanometers across, and this size was determined to be ideal for fine tuning sounds in the ear. Humans often have pores that are larger, and these pores do an adequate job of sound discrimination in the human range of hearing, particularly for voices. However, certain mutations in the human ear can make the size of these pores even smaller than that of mice. A certain genetic defect in human ears can make them highly sensitive to variations in frequency, and that heightened sensitivity makes hearing worse rather than better.

Discovering the importance of pore size and viscosity in this tiny gel membrane has important implications both for the human ear and for hearing aid technology. Researchers now imagine what improvements could be made if ears could be medically modified to improve these problems. However, manipulating such a tiny body part would be quite difficult.


Further Advances in Hearing Loss Technology

In addition to medical interventions, hearing aid technology might benefit greatly from this finding. If a hearing aid were able to mimic the effect of the tectorial membrane, it might be able to assist with distinguishing voices from one another in a crowded space. Hearing aids have made incredible steps toward overcoming difficulties of all kinds, including frequency differences, hearing quiet sounds in noisy places, and even cancelling out ringing in the ears, otherwise known as tinnitus. This innovation might make it possible to tell one voice from another in a crowded space, as well.


Seeking Treatment for Hearing Loss

If you think you could benefit from assistance differentiating one voice from another in a crowded space, the first step is to schedule an appointment with us at Hearing Aid Specialists of the Central Coast for a hearing test. The hearing test itself is completely painless, easy to complete, and often can be very quick.

Following a hearing test, our team will consult with you about the range of innovations in hearing aid technology that can solve all kinds of specific problems hearing. Whereas hearing aids of the past were simply able to raise the overall level of sound in a room, new models can do incredible feats. With these findings about the tectorial membrane, these innovations may go even further.

Don’t hesitate to take the first step in the direction of hearing assistance. You will be amazed at the improvements to your daily life by being able to hear clearly in any environment. Why not schedule your hearing exam with us today?