Do you know why we have two ears?

July 31, 2015
Appareils auditifs Sivantos
In any listening situation, each ear captures sound signals and sends them to both hemispheres (sides) of the brain. While this may seem trivial, it’s the basis of binaural processing—the system that enables us to understand the acoustic information we receive.

The two main advantages of binaural listening are spatial sound localization and speech understanding, particularly in a noisy environment.

Your brain localizes sounds by calculating minute differences in sound timing and intensity between each ear. For example, if the coffeemaker is to your right, the “beep” reaches your right ear before reaching the left ear. In this case, the sound you perceive is slightly louder in the right ear, allowing your brain to determine where the sound is coming from. This function is even more useful when you cross the street and hear a car coming. Generally speaking, localization allows us to gather information about our spatial environment (e.g. room size, ceiling height, and surface textures).

The brain uses three great strategies for understanding speech. The first is binaural redundancy, which gives the brain two chances to interpret words (when sound information is received by each ear). The second strategy is binaural squelch, where the brain favours speech over background noise—helping us comprehend in noisy environments. The third strategy is directed listening, which is a conscious choice to concentrate on a particular person and ignore other sounds or voices.

Unfortunately, hearing loss is highly likely to affect binaural processing functions, which is why many people with hearing loss have trouble understanding in noisy environments.

Binax technology

When hearing loss affects both ears, hearing must be restored symmetrically to facilitate spatial sound localization, spatial perception, and speech understanding in noisy environments. A binaural fitting—where a hearing aid with binax technology is worn in each ear—is therefore recommended. This system is specifically designed to improve speech understanding in noisy environments.

Binaural systems function as single units with dual inputs to process sounds captured by hearing aids. They use noise-reduction technology and directional microphones in a smart new way to offset impairments in natural sound processing functions.

To determine which hearing
aids are best for you, consult an audioprosthetist.