This will be my first post on this forum, and I hope it is in the correct forum.
If anyone knows of a more appropriate forum where this post belongs, please let me know. Thanks!
I have a PC tower on my desk at home (17th floor apartment in a building that was built at least 40 years ago) about 80-100 cm to the right of my keyboard/mouse/monitor setup. I use a "Ttesports" gaming headset that has a microphone on a small boom. The PC uses "on-board sound" (there is no sound card that is plugged into a PCI slot on the motherboard).
There is an annoying background humming sound/noise coming from my headset's headphones whenever the headset's microphone is actively capturing audio input. For example, I used Audacity to record my own voice and upon playback the hum is quite audible.
Using Audacity's Analyze >>> Plot Spectrum tool (I believe) I was able to reliably determine that the sound frequency is approximately 60Hz.
Touching the bare skin of my finger/toe/other appendages to the computer tower case or even the metal tip of the cable input to my modem/router reduces the hum to a barely audible level (however, it is still audible). If I keep one hand in contact with the system in this way and use my other hand to gently touch the microphone on the headset, the 60Hz hum is COMPLETELY gone. No sound, except my excited and bewildered breathing, comes through the headset. Removal of my hand from the microphone reproduces the barely audible form of the hum, and removing my other hand (both hands raised in the air now) the full force of the hum returns.
Last night, I unplugged an old TV (it had what is referred to as a "tube" in it, I believe) which was sitting on the desk within half-a-meter of my head (where my headset is) and the hum was reduced significantly. Also, the presence of a small desk lamp (from Walmart) causes the hum to increase substantially when the headset is anywhere near it while it is plugged in to a power outlet.
If I stand up and walk as far away from the PC tower as possible (approximately 3 meters) the hum is almost completely eliminated (less than the barely audible form described above). Moving closer to the PC tower causes the hum to gradually increase back to the current stable level.
The hum is caused by something in the PC tower. Maybe something in the tower isn't grounded properly? Maybe something in the tower (power supply unit?) is causing the hum, like the old TV or desk lamp?
I want to get rid of this annoying hum. I record audio for use in my own personal software projects as well as communicating over Google Voice and Ventrilo. The hum has got to go.