Diplacusis Test

What it measures

Whether the same sound is heard at a different pitch in each ear — a condition called diplacusis. If your ears disagree, you tune one until they match, yielding an interaural pitch difference (in percent). Diplacusis can be a sign of asymmetric cochlear change and sometimes accompanies Ménière's disease or sudden hearing loss.

How it works

First a 1 kHz tone is played equally to both ears and you say whether the pitch sounds the same. If it differs, your left ear keeps the fixed reference while you slide your right ear's pitch up or down until the two match. The percentage difference at the match point estimates your interaural pitch difference.

Tips for an accurate result

• 1Sudden diplacusis is a red flag — A new pitch mismatch — especially with hearing change in one ear — should be checked promptly.
• 2It can come and go — Diplacusis may fluctuate, particularly in Ménière's; retest on different days.
• 3Pair with the pure-tone test — Asymmetric thresholds often underlie a pitch mismatch between ears.
• 4Note recent ear events — Infections, noise exposure, or a blocked ear can cause temporary diplacusis.