# Medusa - What's the hi-pitch sound on the headphones output when Medusa is not playing?

**URL:** <https://backstage.polyend.com/t/medusa-whats-the-hi-pitch-sound-on-the-headphones-output-when-medusa-is-not-playing/291>\
**Category:** Legacy Products\
**Tags:** frequent-questions, medusa\
**Created:** [December 31, 2022, 11:00pm UTC](https://backstage.polyend.com/t/medusa-whats-the-hi-pitch-sound-on-the-headphones-output-when-medusa-is-not-playing/291 "2022-12-31T23:00:00Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Arek](https://backstage.polyend.com/user_avatar/backstage.polyend.com/arek/32/29_2.png) [@Arek](https://backstage.polyend.com/u/Arek)\
**Post date:** [December 31, 2022, 11:00pm UTC](https://backstage.polyend.com/t/medusa-whats-the-hi-pitch-sound-on-the-headphones-output-when-medusa-is-not-playing/291/1 "2022-12-31T23:00:00Z")

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This is auto-calibration. The analog oscillators are physically running during it so even though their volume is turned all the way down for tuning, you can still hear them a wee bit in the headphone output (only, does not apply to Master out).

In 4.0 auto-calibration is happening much less often as the synthesizer heats up so you shouldn’t be hearing this too often.