Visual-field displacements in human beings evoked by accoustical transients

Area of Science:

• Auditory and Vestibular Science
• Neuroscience
• Human Perception

Background:

• Intense sound exposure can lead to unusual sensory experiences.
• Visual-field displacements have been anecdotally reported during exposure to loud, repetitive sounds.
• The underlying sensory mechanisms for these displacements are not fully understood.

Purpose of the Study:

• To investigate the phenomenon of visual-field displacements caused by intense audiofrequency transients.
• To determine the influence of sound frequency, repetition rate, and transient onset/offset times on these reported displacements.
• To explore the potential role of the vestibular system in mediating these auditory-induced visual effects.

Main Methods:

• Subjects were exposed to intense (125 dB SPL) repetitive audiofrequency transients.
• Three experiments systematically varied sound frequency (100-5000 Hz), repetition rate (0.5-6.0 Hz), and transient onset/offset times (0.2-25 ms).
• Participants reported perceived visual-field displacements and motion magnitudes.

Main Results:

• Sixty-two out of 133 subjects reported visual-field displacements.
• The most significant displacement reports and perceived motion magnitudes occurred between 500-1000 Hz at approximately 1 Hz repetition rate.
• Onset/offset time variations showed inconsistent effects on reported displacements.

Conclusions:

• The findings suggest that intense sound can stimulate vestibular system receptors, causing visual-field displacements.
• This vestibular stimulation may explain previously observed discrepancies in infrasound-evoked eye movements.
• Prolonged or intense sound exposure might lead to vestibular receptor damage, independent of auditory damage.