It's the first thing most people ask. The honest answer is: sometimes, it depends on the cause, and there's much less research than you'd hope. Here's what is known.
About half of people with sudden hearing loss get some or all of their hearing back on their own, usually within one to two weeks, and early treatment improves the odds. In one carefully measured case, a patient's hearing recovered fully within four weeks of steroid treatment, and their diplacusis returned to normal shortly after. One case isn't proof, but it fits what you'd expect: if the inner ear heals, its pitch map can go back to normal.
With Ménière's disease, diplacusis is linked to fluid build-up in the inner ear, which rises and falls. People with Ménière's often notice the pitch getting worse and better along with their other symptoms.
Some of the best evidence that adult pitch perception can change comes from cochlear implants. When someone first gets an implant, a given electrode often sounds far higher or lower in pitch than expected. Studies that followed implant users found the pitch they heard shifted over months and years, sometimes by as much as two octaves. In people who still had some natural hearing, it moved toward the pitch their natural hearing heard. The brain seemed to use the natural hearing as a reference and recalibrate the implant.
That doesn't mean it always happens. Some implant users don't adapt, or adapt the other way, and an implant isn't the same as diplacusis. But it shows adult pitch perception isn't fixed. Researchers studying diplacusis have written that, over time, the brain's plasticity "can be expected to reduce" it. That's a reasonable expectation, not yet a measured result.
Practice also changes pitch hearing: people's ability to tell close pitches apart measurably improves with training. Whether practice can reduce a mismatch between the ears hasn't been studied.
Because there's so little research, your own data is the most useful evidence you'll have. A mismatch measured the same way every week or two shows whether yours is improving, holding steady or getting worse. That's worth sharing with your audiologist, and it's reassuring when it's improving. How you feel music sounds on a given day can swing with tiredness, noise and mood; a measurement is steadier.
To be meaningful, measurements need to be comparable:
Harmonic Recovery does exactly this, and marks changes smaller than your own normal variation as "no clear change" rather than overclaiming progress.
A new or worsening pitch change needs a doctor. If diplacusis appears suddenly, or gets worse along with hearing loss, dizziness or a full feeling in the ear, have it checked rather than waiting to see if it passes.
This page summarizes published research and public health sources for general information. It is not medical advice. An ENT or audiologist can examine your ears and tell you what applies to you.
Harmonic Recovery
A headphone setup tuned to each of your ears, a pitch-matching check at six frequencies, a pitch hint that plays in your other ear while you listen to your own songs, 3-minute drills, and a chart that shows whether anything is changing. Free to start.
On a computer? Scan with your phone's camera to open the app in its store.
