This article is from the Tinnitus FAQ, by email@example.com (Mark Bixby) with numerous contributions by others.
Masking is the technique of producing external "white noise" sounds that
will mask the tinnitus and make it less distracting. Masking machines come
in both in-the-ear and portable models that produce sounds ranging from
random white noise to waterfalls to surf, etc. Frequencies used are
generally within a 1 khz - 12 khz band. Hearing aids can also function as
maskers by amplifying external sounds. Many people find that tuning a
regular FM radio to an empty frequency and listening to the static
beneficial. Another popular method is to run an electric fan. If you have
an audio CD player, consider putting on a nature sounds (ocean, jungle,
whales, etc) CD in autorepeat mode before going to bed.
In a study of masking, 16% of patients reported relief with a hearing aid
alone, 21% reported relief from a tinnitus masker alone, and 63% reported
relief from a combination hearing aid / tinnitus masker. In the latter case
it was important to properly adjust the hearing aid before attempting