Same issue! 1hr45 into a bike ride with my AirPods Pro3 in transparency, Adaptive, or Noise cancellation mode they will start making a high pitch feedback loop noise in the Left AirPod, and then the right side will start after about 2hr45.
This will continue for the remainder of the ride. About 3 hours after finishing riding the noise will gradually go away. Turning off ‘Listening mode’ also makes the noise go away, but as soon as it is switched back on the noise returns.
I can disconnect from all Bluetoofh devices, and it makes no difference. I connect to my iPad, it makes no difference. Swap out the eartips/ rotate the eartips – makes no difference.
This happens Every time I ride my bike for more than 1 hr 45 – without exception. I have been through all
troubleshooting procedures under the guidance of senior Apple Technicians and no difference.
I returned my first pair of Pro 3 and they replaced them, but the replacement had the same issue. This is obviously a design / software / and/or manufacture defect and they are not fit for purpose.
Possibly a defective manufacture run and both pairs I received are from the same run?
I have contacted Apple again and are waiting for a response. I have been cycling for years with all versions
of AirPod Pros on the exact same cycle route and never had any issues before. . I have noticed the Pro 3 noise cancelling cuts out the wind noise much better than the previous models which is great! But I suspect whatever they have changed to achieve this has caused the issue.
I can use my AirPods in my office without any issues, however it is a relatively quiet environment. I understand others are experiencing similar issues on Plane flights where the noise cancelling will be working hard to shut out the background hum - similar to the wind on my bike rides... I don't think this is related to altitude as some have suggested, I think it is related to the noise cancelling mechanism / software.