Custom-Built Sound Laser Can Fire Music Directly at Someone
SMRTR summary
A maker built a "sound laser" device that fires music or conversation in a tight beam directly at specific people while others nearby hear nothing. The contraption uses 73 piezoelectric transducers to generate ultrasonic waves at 40 kHz that carry audio signals, which air pressure naturally converts back to audible sound, creating effective targeted audio transmission over 100 meters.
SMRTR provides this summary for quick context. The original article belongs to TechEBlog.
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