Audible Enclaves and PAL Technology | 05 Apr 2025

Source: TH 

Sound waves are longitudinal, propagating through compression and rarefaction, but they also spread due to diffraction, leading to dispersion (which increases with frequency), making precise sound delivery to a specific individual difficult in noisy environments. 

• However, audible enclaves and parametric array loudspeakers (PAL) solve this by focusing sound into narrow beams, ensuring only the intended listener hears it. 
• Audible Enclaves (AE): These are focused pockets of sound created using 2 high-frequency waves that are individually inaudible but produce audible sound at specific locations through nonlinear interactions.  
  • This ensures precision sound delivery without external disturbance, enhancing privacy and customization.  
• PAL: PAL uses high-frequency ultrasonic waves modulated with an audio signal to create a highly directional sound beam, ensuring only targeted listeners hear the audio.  
  • By self-demodulating in the air, they generate focused sound while preventing unwanted dispersion.  
• Applications of PAL and AE: PAL and AE find applications in museums, retail, public announcements, immersive entertainment, assistive technology, and security, offering precise audio without disturbing surrounding areas.