Recording Tones Go Faint


So for our Physics investigatory project, we are using Audacity to record the reflectivity of sound waves on metal using tones set at certain Hz that can be recorded and produced by our laptops. We use two laptops for this setup, one for producing the tone and the other for recording using a regular microphone with 60-13,000 Hz range. We are experiencing problems recording. The tone recorded suddenly goes faint after three to four seconds when we try to listen to the playback, and we are not able to determine where the problem is coming from. We are unsure if it is the microphone used, or the speakers used, or a setting in Audacity itself, so I hope someone can help us with this one.

Thank you in advance!

If the problem is in the recording, my guess is that Windows “sound enhancements” are enabled and need to be turned off. See:

If the laptop is deciding you are doing a conference, Skype or communication session, it will test for voice and suppress any sustained tones or sounds figuring them for interference. Voices work OK and music doesn’t.

You should also note that you are working with two different clock signals in the computers. The tone generator may not have exactly the same pitch/frequency as the recorder. Most people run into this problem by making a dual recording of an interview or other podcast show. After an hour of this, it’s not unusual for the two capture sessions to noticeably miss each other in time when played back.

You should know that if that kind of innacuracy affects your work.