In adults with moderate hearing loss and chronic tonal tinnitus, hearing aid amplification schemes adjusted to tinnitus pitch—either by boosting frequencies at the tinnitus frequency or applying a 60 dB notch filter—do not produce a clinically significant reduction in tinnitus handicap compared to standard NAL-NL2 amplification, as measured by the Tinnitus Functional Index after four weeks of use.

When the brain hears sounds, it maps them to specific spots based on pitch. In people with hearing loss and ringing in the ears, some of these spots become overactive and keep firing even without sound. Hearing aids that either boost or block the exact ringing pitch change the sound input, but the overactive brain spots do not calm down because the underlying neural pattern has become fixed. The brain continues to generate the ringing sound regardless of the hearing aid setting, so the person still feels bothered by it.