A 14 second seamless loop of a radio tuned between stations: a band of soft static with a slow drift across the dial, sparse crackle on top, a thin 2.4 kHz whistle that almost becomes a station, and 50 Hz mains hum underneath. Use it for abandoned rooms, night driving, radio scenes, or a background that should sound like nothing is being said.
static: white noise, band-pass drifting 1.1 kHz <-> 1.9 kHz (one slow pass, 1 cycle in 14 s), Q 0.8 air: white noise, low-pass 320 Hz, Q 0.6, at 45% level (the "body" of the room) crackle: about 8-15 bursts a second (fixed seed), each 1.5 ms of noise with a random level, some arriving two or three in a row hum: sine 50 Hz at 0.028, plus 100 Hz at 0.012 whistle: sine at 2400 Hz drifting 2.2 <-> 2.6 kHz on the same 1/14 Hz cycle, level 0.022, written as phase accumulation so the pitch does not drift with time (2400 x 14 s is a whole number of cycles, so the seam is continuous) speaker: high-pass 300 Hz, low-pass 4 kHz (a small radio speaker) seam: 0.6 s rendered past the end and equal-power crossfaded (sin/cos) back onto the head noise seeds: 341 (static), 342 (air), 343 (crackle)