USB microphone unusable in Windows 8 guest

[Andrey Gerasimenko]

With the latest OS X host on a mid 2011 MacMini and Windows 8 32 bit guest, the guest microphone hears loud noise whenever a USB input device (camera or earphones) is selected in host. The only way to get rid of the noise is to set the guest microphone sensitivity to zero. When the line input is selected in the host, the microphone properly hears nothing.

This resembles #5869, but I cannot find the problem in the known issues, so this may be a new bug.

[KCBaltz]

I'm also seeing this issue with a MacBook Pro running OS X 10.10 Yosemite, VirtualBox 4.3.20, Windows 7 Guest. Audio input works from the built-in mic, but when I use a USB mic, I get static on the guest. I've read this is a result of the USB input having a sample rate (16,000hz) that doesn't match the Windows 7 High Definition Audio Device (44,100hz). Not sure if that helps. I haven't found a way to adjust either end of that mismatch.

[batspeck]

Same issue with a MacBook Pro Mid 2010 (16GB RAM, 500 GB SSD) running OS X 10.10.4 Yosemite, VirtualBox 4.3.30, Windows 8.1 Guest, using SpeechMike Premium LFH3500/00. Actually I have just upgraded to VirtualBox 5.0.0 but I don't have my USB mic right now to test it. But I don't think I'll get much improvement. I use the mic for speech recognition on medical radiology reports in brazilian portuguese. There's no Mac OS version yet, only for US english. As stated above, I have to use my iphone headphone mic on audio input for it to work well. When I use the USB SpeechMike, voice recognition sucks.. That sample rate problem makes sense. Does VirtualBox developer team see this comments and tickets?