A slow swell, about as fast as a calm breath.

Why it works

This is pink noise with the top removed and a long, deep rise and fall laid over it, roughly one swell every ten seconds. Two slow cycles drive the level, and because their lengths share no common multiple, the shape drifts and does not return. It is not a recording of the sea, and does not pretend to be one.

Slow, regular sound invites slow, regular breathing, and that is as far as sound goes. The story takes over where the swell leaves off. It has people in it, a place, a small question, and nothing whatever depending on the answer.

What you are hearing

• Slow swell. Pink noise low-passed at 900 Hz, with a long rise and fall about every ten seconds that never lands in quite the same place twice. It is not a recording of the sea.
• 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.