25 High-fidelity Soothing Sounds There are 4 sound categories, 5 white noises (Soft, Brown, Pink, Blue, White Noise), 5 fan sounds (Soft, 2*Household, Industrial, Lound), 5 Light music (3*Lullabies, Meditation) and 10 natural sounds (Fire, WaterDrop, Rain Thunder, Wave ) and so on. The sound rhythm helps you fall asleep, and the white noise machine can effectively cover up destructive or startling sounds to protect your sleep quality. Humanized Memory Design The machine has a unique memory function. The settings in each sound category will be memorized separately, and settings for volume, track and timer can be remembered. It can be used for office, sleep and parent-child interaction, etc. 5 Timer Settings There are 5 timer options, continuously play, 1 hour, 2 hours, 3 hours and 4 hours, you can set it according to your needs.