Sound Masker generates White, Pink, Brown , Purple and Blue noise. You can mix and match combinations and record the output straight to a .wav file. You can also save as many of your configurations as you like, so you may configure one to help you sleep at night and another to mask air conditioning noise throughout the day. Uses include to block PC Fan noise, to block noise from air conditioning units etc. Can also be used as a sleep aid or to help keep conversations private.