Every day we use five senses to navigate ourselves around the world. These five senses are touch, taste, smell, sight and hearing. Typically we notice if something tastes different, we can’t feel something, we can’t smell dinner cooking or if we are not seeing clearly. But, do we always notice that we are not hearing sounds? Similar to our other senses, our ears are very sensitive and require sound in order to stay healthy.
The auditory system is arranged tonotopically, which means that certain areas of the cochlea (inner ear), eighth nerve and central mechanisms are responsible for certain frequencies. This suggests that if certain frequencies of the inner ear are deprived of sound,
the individual will not hear those sounds. This limits the function of the frequency areas and results in a reduction in the understanding of speech.
The most common form of adult hearing loss is a high frequency sensorineural hearing loss. High frequency information provides us with the ability to hear the consonant sounds of speech. This gives us our clarity of speech and our ability to differentiate between similar sounding words; i.e., cat vs. hat. Since the damaged ear is not hearing the sound, the auditory nerve does not pass the sound information on to the brain. Over time the brain will forget sounds. Depriving the nerves and pathways of stimulation will starve the ear; eventually causing the rate of information passed to the brain to slow down. (Imagine if you attempted to run freely through a garden path that has been neglected for years; you would have to slow down and watch your every step and take detours!) Once this slow down occurs, sounds can become distorted. The distortion occurs in the inner ear; which is then sent to the brain.
The brain receives this distorted sound, which it tries to make sense of. Often times individuals who suffer from sensory deprivation, will score poorly on tests specifically for word understanding. Even with the appropriate treatment and amplification, the damaged system will always transmit some form of a distorted sound. In order to maximize audibility and understanding, those with poor word
understanding need to rely on more sophisticated hearing aid technology or assistive listening devices.
Auditory sensory deprivation is a condition that is preventable, whether it’s through medical intervention, the use of hearing instruments, or assistive listening devices. Seeking help at the first signs of hearing loss is essential to the early detection and prevention of further auditory sensory deprivation.