https://www.dotbglobal.com/product/impulse-noise-simulator-semi-conductor-type-ins-s220-s420-noiselaboratoryco-ltd/
Impulse Noise Simulator (semi-conductor type) INS-S220 / S420 – NoiseLaboratoryCo.Ltd. - dot B
- This Noise simulator simulates high frequency noises generated by ON/OFF switching at contact points of switches or relays, and arcs caused by electric...
impulse noisesemi conductor
https://mynoise.net/NoiseMachines/propellerNoiseGenerator.php
B-17 Propeller Noise Simulator — Soothing Sound Masker
Turn off the lights, put the headphones on, and crank volume up. Strap yourself into the pilot's seat... and fly back in time!
noise simulatorsoothing sound