The Importance of the Middle Ear Muscles

The acoustic environment in our modern world is dominated by a variety of low frequency sounds that can easily mask the higher frequency human voice. Here the immense importance of the parasympathetically innervated middle ear muscles becomes apparent: Via the hardly known stapes muscle (musculus stapedius), the vagus nerve also regulates the stiffness of the ossicular chain. Only when this is sufficiently stiff is the volume of low-frequency sounds to the inner ear attenuated, which enables us to decode and interpret acoustic stimuli adequately by the cerebrum (Borg & Counter, 1989). If, on the other hand, the organism does not succeed in attenuating the low-frequency sounds, a massive flooding of the organism with acoustic stimuli occurs, which puts the organism into a state of constant alert. As a result, various behavioural disorders can develop. In addition, it is usually extremely difficult for those affected to understand the content of human speech. Typical consequences can then be disturbances of speech comprehension or pronunciation, but also concentration and memory problems occur more frequently.