It is simply the garbage in garbage out principle.
Electricity come in from the wall, and your audio gear converts that electricity, which goes to your speakers causing them to move and create sound. If the electricity has a sound already (noise), then that will affect the conversion that happens in the audio gear.
Plug a television into the same wall plug as a refrigerator while it is running and see what happens to the picture and the sound.
Electricity come in from the wall, and your audio gear converts that electricity, which goes to your speakers causing them to move and create sound. If the electricity has a sound already (noise), then that will affect the conversion that happens in the audio gear.
Plug a television into the same wall plug as a refrigerator while it is running and see what happens to the picture and the sound.