Static noise at 3.6 between pink and brown, no modulation, 30-second fade
Preview plays right here. The generator adds a sleep timer, full controls, and WAV export.
Delta Waves is the brightest of the sleep presets, comparable to steady rain on a car roof rather than distant thunder. There is a clear soft hiss over the rumble, so it masks higher-pitched sounds like voices and clinking dishes better than the darker options do.
Its color value of 3.6 places it just past the midpoint between pink and brown. The pulse is off, so the level is completely steady, and grey EQ is off too. A 30-second fade-in gives the sound time to arrive without any sense of it switching on.
This is a popular choice for people who fall asleep well to pink noise but want something a shade warmer for the night. Lucid Dream is the darker unmodulated sibling at 3.8, and Drift Away is the nearest pulsing option, at 3.7 with a ten-second swell.