White noise, Pink noise, mais aussi beaucoup d'autres ''couleurs''....
Pour les daltoniens il y a aussi les sweep tones
Intérressant cet article.Gray noise sounds the same at every frequency; like pink, it’s calibrated to sound more balanced to the human ear. There is no single example of gray noise, because every human has a slightly different hearing curve. In medicine, it’s used to treat hyperacusis, an increased sensitivity to normal sounds, or tinnitus, a ringing in the ear.