Testtonen

https://forum.xojo.com/30275-sound-generator/0

https://developer.apple.com/documentation/avfoundation/audio_track_engineering

https://www.blackcatsystems.com/software/audio-function-generator-software.html

www.nch.com.au/tonegen/index.html

Terts

https://nl.wikipedia.org/wiki/Resolutie_(geluidsmeting)#Tertsbanden_of_1/3_octaafbanden https://www.engineeringtoolbox.com/octave-bands-frequency-limits-d_1602.html