【Multiple sounds】Total 6 sound options, 5 sound tracks each, providing a wide selection of white, pink and brown noise such as fan, rain, thunder, forest, birds, ocean waves, brook, and fetal heartbeat, etc 【Shielding noise】Sleep therapy machine provides 32 volume levels from very quiet to loud, lets you take control of your sound environment, efficiently masking unwanted noise 【Set timer】The sound machine therapeutic sounds can be used for relaxation, sleep, travel, work, study or meditation. You can set a 30/60-minute timer or play continuously.