Apple's keyless keyboard

Apple has patented a design for a keyless keyboard.
The glass topped design features no moving parts but instead works using acoustic and piezo-electric sensors.
The system compares sounds made by tapping of the screen to a database of signatures determining which key is being used.
The keyboard would still display the traditional Qwerty keys but three sensors within the keyboard would be “sufficiently precise” to triangulate the position of the tap said the patent filing.