US Patent 7599503 Audio output level setting method and device

In a device equipped with an audio output, a range of the audio output level in regular use is set. When an attempt is made to change the setting to a volume level exceeding the range of the audio output level having been set, a request is made for an acknowledgement that the operation is appropriate, and only if a reply is received within a given time, is the volume setting changed. Such a method prevents the audio output from a television set or audio equipment to be increased to a volume level higher than necessary due to an operating error in a volume setting operation.