Acoustic Feedback
The high-pitched whistling or squealing sound produced when amplified sound from a hearing aid's receiver leaks back to its microphone and is re-amplified, creating an unwanted feedback loop.
Full Definition
Acoustic feedback in hearing aids occurs when sound emitted from the receiver (speaker) escapes from the ear canal—due to a poor ear mould seal, high gain settings, or proximity to a reflective surface—and is picked up by the device's microphone, triggering a cycle of re-amplification that produces a characteristic whistle or squeal. Modern digital hearing aids employ active feedback management (AFM) or feedback cancellation algorithms to suppress this phenomenon. In clinical documentation, 'acoustic feedback' should be distinguished from 'microphone feedback' or 'electrical feedback,' which have different origins. Editors should note that feedback is frequently described colloquially as 'whistling,' and may need to standardise terminology in patient-reported outcome documents.
Usage
Usage note: Write as two words: 'acoustic feedback.' Do not conflate with tinnitus (which is an internally generated sound). In formal clinical writing, do not substitute the colloquial 'whistling' for the technical term without definition.
In Context
- "The patient's complaint of a persistent whistle was attributed to acoustic feedback resulting from a poorly retained ear mould." — Hearing aid troubleshooting clinical note
- "Patient-reported outcome forms may use 'whistling' colloquially, but editorial consistency requires standardisation to 'acoustic feedback' in all clinical summaries." — Audiology outcomes data editorial protocol