There's another possible explanation for this, depending on how the white noise machine is built.
Unshielded speakers can act as AM radio receivers. I've had old speakers play extremely faint music while not plugged into anything; a few minutes later it identified itself as the local radio station.
Many AM radio stations are permitted to crank up their transmit power at night, exactly when many people might use white noise to sleep.
When I was taking my electronics courses, it was fairly difficult to not build an AM receiver. Any time we were working with PLL or high gain amplifiers attached to a speaker, you'd eventually hear AM talk radio come out of someone's project.
Comments
There's another possible explanation for this, depending on how the white noise machine is built.
Unshielded speakers can act as AM radio receivers. I've had old speakers play extremely faint music while not plugged into anything; a few minutes later it identified itself as the local radio station.
Many AM radio stations are permitted to crank up their transmit power at night, exactly when many people might use white noise to sleep.
It's wild how easily things can act as AM receivers. A pencil and rusty razor, or a tooth filling and saliva.
When I was taking my electronics courses, it was fairly difficult to not build an AM receiver. Any time we were working with PLL or high gain amplifiers attached to a speaker, you'd eventually hear AM talk radio come out of someone's project.
Yeah, it's just a bandpass filter (very easy to make by accident) and an amp.