Something to listen to in bed.

Why it works

The requirements for bedtime listening are stricter than they look. It should not be bright, loud, funny or suspenseful. It should not end abruptly or be followed by something else. It should be dull enough to leave and pleasant enough to stay with. Very little made for daytime passes.

This was made for the purpose. The noise is pink, soft, and generated live. The story is the opening of one about Aristotle, read slowly, with its ending already given away. The whole thing lowers itself to silence at four minutes. The full stories in the app do the same, later and more gradually.

What you are hearing

• Pink noise. Equal energy in every octave, made with Paul Kellet's pinking filter and rolled off above 2,500 Hz. Brighter than brown, softer than white.
• 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.