I buy this for my child to sleep to the nature sound . after buy it , I find you can only play the nature sound in the `` sleep '' mode and that they will only play for a maximum of 59 minute , and then it shut off ! why can not it just also have a `` on '' and `` off '' button ? also , there be no volume control for the sound , and most seem pretty loud , but `` ocean '' be the softest . further , the sound repeat after a very short time , about 3 seconds , so the pattern be very obvious and could get annoying . I would say to look for a better product with more feature .