Screeching Noise With Olympus LS 100

I’m using Audacity 2.0.0 on with Windows 7 64 bit. I’m using an Olympus LS 100 pcm recorder as a usb microphone to record music. When I play the recording, it starts off good, but near the middle or end of the recording, I hear a loud screeching noise that distorts the audio. Does anyone know why this is happening?

Do you have speakers playing?
When using a microphone you need to use headphones rather than speakers so as to avoid screeching/howling feedback.

Yes, I use headphones when I record.

Could you post a short audio sample of the screeching as it starts.
Aee here for how to post audio files:

Thank you for posting your issue about the Olympus LS-100 Linear PCM Recorder. A firmware update is available via the following link to correct the issue you are having.