From Vectormedia Software:
Sound Masker is a complete replacement for hardware noise masking products. You can mix and match various combinations of noise until the desired masking effect is achieved - and playback the output in realtime via speakers, or alternatively record the output to WAV or MP3 format, ready to create your own custom white noise masking CDs or MP3s to listen to anywhere. You can also save as many of your configurations as you like, so you may save one to help you sleep at night and another to mask noise throughout the day. Soundmasker is completely customizable and is ideal for home or office sound masking. Soundmasker is extremely easy to setup and use - no previous experience is required, yet is powerful enough to rival professional hardware noise masking solutions costing hundreds of dollars.