Sound Clarity and Speech Perception
I can hear you, but I can’t understand you.
Healthy hearing is much more than the audibility (loudness) of sound. Sound clarity and speech perception, or understanding speech and recognizing words, are just as important.
The inner ear is lined with two types of cells called “hair cells” – inner hair cells and outer hair cells. Outer hair cells are responsible for amplifying, tuning and filtering sounds, while inner hair cells convert sounds into electrical signals carried to the brain. The loss of either cell types leads to a decrease in sound sensitivity, clarity and intelligibility.
Critical information lost at high frequencies
Today’s treatments for hearing loss – amplifying devices such as hearing aids – are limited in their ability to improve speech perception and clarity, as they cannot replace the tuning and filtering of lost hair cells. This often translates into difficulties understanding speech and following conversations – often in noisy backgrounds.
Additionally, most acquired SNHL begins at the base of the cochlea (20,000 Hz) and moves down toward the 4,000 Hz range. High frequency hearing loss is associated with problems understanding speech, because a lot of speech sounds – especially “s,” “f” and “th” – are high frequency, soft sounds. When you can’t hear these consonants, it can be very difficult to recognize words.
Add all this together, and millions of people with hearing loss continue to struggle with speech perception, even when using assistive devices.
Speech Perception and Quality of Life
Hearing is how we communicate and relate to one another. It’s an important part of our social and emotional well-being.
Any degree of hearing loss can be damaging to relationships – personally and professionally. Friends, coworkers and significant others often do not understand how hearing loss can impact someone’s life, and often do not know what to do to communicate effectively.
To struggle with understanding speech can also be exhausting, emotional and isolating for someone with hearing loss. Many people decide to avoid social situations, especially in environments where there may be background noise.