Why does sound stimulation not cause dizziness?

BACKGROUND

Sound waves stimulate the saccule. Therefore, sound waves are transmitted from the perilymph to the endolymph, causing the otolithic membrane of the saccule to vibrate and the cilia of the hair cells to move. Nevertheless, dizziness does not occur in response to auditory stimuli. To investigate this mystery, we examined the presence or absence of dizziness and nystagmus when loud sounds were presented to healthy individuals and reconsidered the auditory reception mechanism.

METHODS

Ten healthy individuals without ear pathology were studied. Stapedial reflex testing was performed on both ears using an impedance audiometer and the occurrence of dizziness and nystagmus was examined.

RESULTS

None of the subjects complained of dizziness or showed nystagmus.

CONCLUSIONS

The saccule does not cause nystagmus or dizziness. Sound waves do not stimulate the lateral semicircular canal, this means that sound waves selectively stimulate the saccule (i.e., no vertical expansion). As an auditory mechanism, we propose the endolymph conduction theory, in which sound waves are transmitted through the ductus reuniens to the endolymph of the cochlear duct and directly bend the cilia of the hair cells. This is more scientific and credible than Bekesy's traveling wave theory.