Researchers have designed a sound that is completely inaudible to humans (40 kHz or above) yet is audible to any microphone. The sound combines multiple tones that, when interacting with the ...

SINGAPORE (Reuters) - Ultrasound - inaudible sound waves normally associated with cancer treatments and monitoring the unborn - may change the way we interact with our mobile devices. Couple that with ...

In a development likely to concern those who believe that a system that’s not connected to a network is safe from surveillance, researchers have demonstrated that microphones and speakers built into ...

Microphones, from those in smartphones to hearing aids, are built specifically to hear the human voice -- humans can't hear at levels higher than 20 kHz, and microphones max out at around 24 kHz, ...