presbyacusis
Last reviewed 01/2018
Presbyacusis is the progressive, sensorineural hearing loss that occurs with age. It is typically bilateral and symmetrical, and is very common after 55 years of age. It results from a gradual loss of cochlea hair cells and degeneration in the cochlea nerve.
Characteristically, high frequency perception is lost making it difficult to understand speech. The loss is particularly disabling as most consonants are in the high frequency range. Words may merge into one another so that speech is muffled.
Individuals can usually cope with conversation on a one to one basis, but their hearing is useless in crowded rooms as their limited high frequency perception is overwhelmed by the barrage of low frequency sound.
The dynamic range of hearing is also reduced due to the phenomenon of recruitment, which explains why shouting at these individuals usually worsens their hearing.