A 14 second seamless loop of quiet room tone: a low filtered rumble, a faint air-conditioning hum, a thin layer of air, and a faint wash of distant traffic that swells and fades about every seven seconds. Use it under dialogue, voice-over or thin video scenes so the silence stops sounding like a broken microphone.
bed: white noise, low-pass 300 Hz, Q 0.6 traffic: white noise, band-pass 140 Hz, Q 0.8, with a 1/7 Hz swell (exactly 2 cycles per 14 s), level swings 0.6 to 1.0 air: white noise, band-pass 900 Hz, Q 0.5 hum: sine 58 Hz at 0.015 and 116 Hz at 0.006, drift 2/7 Hz (exactly 4 cycles in 14 s) seam: 0.6 s rendered past the end and equal-power crossfaded (sin/cos) back onto the head noise seeds: 55 (bed), 56 (air), 57 (traffic)