Btw, I've already tried some noise generators for Android and I've observed strange effect - I have ringing only in the left ear so I used only one ear bud with the generator. Then when I turned it off, it induced noise in the other ear. It was like the brain was generating signal to compensate for the external noise in the left ear and when the noise generator was turned off, the spurious signal in the right ear became hearable. Fortunately this effect was only temporal.
Btw, I've already tried some noise generators for Android and I've observed strange effect - I have ringing only in the left ear so I used only one ear bud with the generator. Then when I turned it off, it induced noise in the other ear. It was like the brain was generating signal to compensate for the external noise in the left ear and when the noise generator was turned off, the spurious signal in the right ear became hearable. Fortunately this effect was only temporal.