Seems like we have enough nearby, always-on biosensors to do cool things now, like:

You have a "pool" of oscillators. They are tuned to white noise, which you seek out from time to time to drive out the thoughts [just play along].

But your smart watch, which knows what your heartbeat is, can choose to make the noise pink-er; your heart rate goes up, it sounds more pink, which makes sense in two ways:

1. You are adding higher frequency noise `cause your higher frequency heart.
2. Pink noise is busy and unpleasant.

Likewise and contra-wise, if your heart rate goes down, the noise gets browner.

1. More a pleasant rumble, ideally, than a shrieking waterfall.
2. Heh, "brown".

Make it so!