The Gro-hush has been tested to the relevant toy safety standards including EN71, US Toy Standard ASTM F963 and the Consumer Product Safety Improvement Act. The Sound levels have been set at a volume that is safe for continuous sound as stated by the Children Hearing Institute in New York. It is not possible to alter the sound levels of the Gro-hush so you can’t have it too loud. Always ensure that you are using the Gro-hush as recommended in the Operations Instructions- always use it with the cushioned cover attached. The Gro-hush also switches off automatically after 10 minutes – you can use the Gro-hush for longer but you need to select the sound again.