Semicircular Canals
Three fluid-filled canals in the ear that help maintain balance.

Sensorineural Hearing Loss
Occurs as a result of damage in or a defect of the inner ear (cochlea or auditory nerve).

Severe Hearing Loss
Hearing loss of 71 to 90 dB. An individual with this loss may understand loud speech at a distance of 1 foot in a quiet environment.

Signal to Noise Ratio
The relationship between the intensity of speech and the intensity of noise; ideally speech should be 6 dB or greater for satisfactory communication.

Sound Wave
Pressure wave set in motion by any event that generates energy. This pressure wave is detected by the hearing mechanism as sound.

Speech Awareness
The softest level that speech can be detected.

Speech Reception Threshold
The softest level that words can be accurately repeated 50% of the time.

Stapedectomy
Surgical removal of the stapes which is replaced by a prosthesis; used to correct otosclerosis.

Stapes (stirrup)
Small bone, shaped like a stirrup, attached to the incus and the oval window; amplifies sound waves coming from the outer ear.