https://devzone.nordicsemi.com/f/nordic-q-a/39389/sr3-v1-2-anr-question-active-noise-reductionhi , I use SR3 V1.2 to test. I enable ANR, play the recording directly in the loop. About every five seconds, a second or so of unusual sound appears. The rest of the time sound is normal. When I disable ANR, there won&#39;t be this one-second sounden-USTelligent Community 13Fri, 12 Oct 2018 11:39:34 GMThttps://devzone.nordicsemi.com/thread/152676?ContentTypeID=1Fri, 12 Oct 2018 11:39:34 GMT137ad170-7792-4731-bb38-c0d22fbe4515:c196e0db-f433-4482-bda4-978a95e085c9bjorn-spockeli<p>Hi Judge,</p> <p>please refer the&nbsp;&nbsp;nRFready Smart Remote 3 nRF52 Firmware Version 1.2.1&nbsp;Release notes</p> <ul> <li>When the Active Noise Reduction (ANR) functionality is enabled, beeps are added to the signal at regular intervals. For full, unrestricted version of the ANR functionality, contact<span>&nbsp;</span><a href="http://www.vocal.com/noise-reduction/adaptive-noise-reduction/" rel="noopener noreferrer" target="_blank">vocal.com&reg;</a>.</li> </ul> <p>Best regards</p> <p>Bj&oslash;rn&nbsp;</p><div style="clear:both;"></div>