I don’t know if this is related to Windows 10, but I didn’t have this problem before updating.
When I record, using my “computer mic” into the front mic input on my computer, the monitored sound is fine, but when I play it back, the pitch (not the speed) is an octave or more lower. My voice sounds like a very bad Darth Vader.
I tried recording my voice with my old version of Sound Forge, and it comes out fine.
I was able to use Audacity by running my studio type mic into a pre-amp to the computer’s external audio input jacks, and that sounds fine. It’s just recording with the Front Mic input that’s all messed up.
My audio driver was up to date. There was a new chipset driver, but that didn’t help.
I did find something weird though.
With Audacity set to use the front computer mic for all of the following…
Changing the “default” sound device had an effect. One of the devices made the playback raise the pitch, stereo mix, made the mic playback work correctly, then going back to my normal default, my webcam mic, and the front mic still worked right. Then I ran the speech recognition setup, and the the front mic was back to the super low pitch. Toggling the default to stereo mix, testing, and back to the webcam mic, and the front mic worked again. BTW, the webcam mic worked all along.
I don’t know what’s going on, but I guess I just won’t be lazy anymore, and use my good mic, preamp, and aux audio input for my recordings. The webcam mic works fine for Cortana.
If you have not already done so, you need to go to the computer manufacturer’s site to look for Windows 10 audio drivers for your computer model. Device Manager saying the drivers are up-to-date may not be sufficient.
I’m sure I have the latest driver because a couple of days ago, I noticed that the Stereo Mix option was missing. The Windows 10 update had replaced the Dell driver with its own. I downloaded and installed the Conexant SmartAudio HD driver from Dell at that time, which returned the Stereo Mix option.
The real culprit seems to be the sound enhancements as you said. I checked that the other day, but apparently, each sound input device has its own properties. I must have been checking the properties of my webcam mic and not the “front” mic, because, the front mic has a check box for “sound enhancements”, that does not appear on the webcam advanced settings. I ran several tests, and the pitch is always incorrect on playback with recordings made with the sound enhancements box checked for the front mic, and it’s always correct with the sound enhancements box unchecked.