Almost pure brown noise that swells and settles once every eight seconds
Preview plays right here. The generator adds a sleep timer, full controls, and WAV export.
Deep Sleep sounds like a large fan running behind a closed door, or a highway heard from a bedroom half a mile away. There is almost no treble in it at all, just a broad low roar that rises and falls so slowly you tend to stop noticing the movement after a minute or two.
The color sits at 3.95 on the scale, one small step short of full brown, so the top end is rolled off at roughly 6 dB per octave. A sine-shaped pulse at 0.12 Hz lifts and lowers the volume once every eight seconds or so, and the whole thing fades in over 30 seconds so nothing startles you as you settle.
Most people leave this running all night, either through a speaker or a single earbud. Compared with Heavy Blanket, which is flat and unmodulated, Deep Sleep has a gentle breathing motion. Womb Sound adds grey equalization and pulses more slowly, every twelve and a half seconds.