A report is given of a patient who produces a continuous high-pitched tone (3,400 hertz 10 Hz—35 dB sound pressure level) from her right ear.
The tone is not audible to the patient. She has a circumscribed sensorineural threshold dip with a maximum of 35 dB at 3,500 Hz. The sound appeared to be emitted by the ear drum and is probably a result of an anomaly of the venous system at the base of the skull near the ear.
The threshold dip at about the same frequency as the tone remains unexplained.