Sounds for a brain that gets busy at night.

Why it works

Some brains save their best work for bedtime. The lights go off and the meeting starts: plans, replays, a song from 2009. Trying to adjourn it tends to fail, because trying is more activity. It works better to give the meeting a dull item to discuss.

That is what plays here. Under it is brown noise, low and without a loop. Over it is a story about a philosopher and some tide pools, read at a pace that makes hurry seem silly. It is true, so it is worth a little attention, and it is long over, so it needs none.

What you are hearing

• Brown noise. White noise run through a leaky integrator, so its energy falls six decibels per octave, then low-passed at 400 Hz. A low, even wash.
• The voice. The first four minutes of Aristotle, the Greatest Philosopher, a Lullable story, in a synthesised voice. It only plays if you bring it in.
• The ending. The preview lasts four minutes. Its last ten seconds are a straight fade to silence, so it never stops abruptly.

For a real recording that runs forty minutes, the Lullable iPhone app has rain, waves, a campfire and plain noise, with no voice and no music.