Switch groupings should be identifiable by touch. The power switch should be clearly separated from the other switches. It should be possible to find the battery cover by touch. Membrane keypads should have tactile markings on the key surfaces to enable identification by touch. Ensure closely located buttons are not easily pressed together.
Most people are comfortable with the arrangement on push-button telephones.
It should be clear to the user when a sleep mode has been performed. Where left and right plugs are used, there should be a protruding point adjacent to the terminal for the left plug. Status Confirmation Principles Should be possible to determine product is powered on or off by touch. Operations should produce a clear response, such as a click, or tone,etc. Toggle control reference points should be clear producing a click, or tone.