Thanks for posting. I am so sorry to hear about that. I would recommend contacting your local support team for assistance. Here is a link you can use. Click on your country, scroll down until you see "Contact Us."
Tony G - Community Support
Thanks for updating us. I would give your local support team a call to check on this. Here is a link with contact information.
Jan 13, 2019
I am experiencing the same issue.
I purchased a QC 25 in November 2018 for the first time. It was working very well. It was used with care and put back in the case after each use.
About 1,5 months later, suddenly and without apparent reason (it was simply in use, it didn't hit anything and did not fall once), the speaker started to make a high pitch sound. It is the same sound that you hear when you put a microphone next to a speaker.
I've tried to remove the battery and wait for 24 hours. It did not resolve the issue.
I returned to the store and despite that they had a 30 day return policy, they replaced the product.
Regrettably, after just 1 week use, the new model also started to make a high pitch sound.
I have no idea what the cause could be. There is a ventilator with heavy sound that is occasionally used, for which the QC25 is used. However, since the product is designed to be used in air planes, an 'overload' may not be a possible cause.
When pressing the ear buds together firmly, the high pitch sound goes away, but when releasing the buds the high pitch sound returns.
I've searched the internet and this forum. This message has been the only report that I found until now.
I hereby want to ask if there is any information available about the issue, what could have caused it and how the issue could be resolved.
1) what could explain the issue?
2) is there a memory and reset functionalty?
Thanks in advance for the support!
Dec 15, 2016
Thanks for writing in and sorry for the trouble you're having. May we get a little more information?
Can you hear this noise when the headset is not worn?
Also, can you verify the screen covered earcup ports are not blocked when using them? Blocked or covered earcup ports may cause squealing, feedback or other audio performance issues.
Let us know when you get the chance.
Thanks for posting. I would like to address what I can.
Also, I would contact your local support team for further assistance. Here is a link you can use. Click on your region, scroll down until you see "Contact Us."