Patent ID: 7013393

Claim:
A secure access card comprising: at least one tone generator for generating tone audio output external from one side of the secure access card, the tone audio output comprising at least one tone signal that is variable in at least one of tone frequency, time duration of tone, time duration of space between tones, and by amplitude of tone, and wherein the at least one tone generator comprises a plurality of acoustic transducers that are mechanically tuned to oscillate about their mechanical resonant frequency to substantially maximize audio power output from each of the plurality of acoustic transducers being oriented outward of the one side of the secure access card for generating, from each of the plurality of acoustic transducers, the tone audio output external to the one side of the secure access card; input means for accepting input from a user; and a controller, electrically coupled to the at least one tone generator and the input means, for controlling the at least one tone generator to generate a tone sequence corresponding to the input from the user, the tone sequence for delivery via a communication network interface, the secure access card being of size and form for convenient carrying and use by a user.