4 ms·

> inaudible sounds What?

• ChrisGranger 8y ago
  Humans have a fairly limited frequency range in which they can hear, typically said to be 20 Hz to 20 kHz, but usually worse than that for most people. There's all kinds of sound in the world that is inaudible to humans.
• ipsum2 8y ago
  TV ads emit inaudible (to humans) sounds to track which ads are being viewed. https://arstechnica.com/tech-policy/2015/11/beware-of-ads-that-use-inaudible-sound-to-link-your-phone-tv-tablet-and-pc/ https://arstechnica.com/tech-policy/2015/11/beware-of-ads-th...
  • learc83 7y ago
    Can average TV speakers emit sounds outside the frequency of human hearing? I didn't think they could.
    • godelski 7y ago
      Yes, most speakers are 20Hz-20kHz or better. Here's a pair of $10 headphones that do just that[0]. Most humans have range inside that band. Those both are really the limits of human hearing and as you get older it dramatically decreases. I remember there were those ringtones (IIRC called cricket?) that used high frequencies so teachers wouldn't hear it go off. Some malls also used high frequency sounds so teens wouldn't loiter outside their stores. Most of these were even below 18kHz. tldr: yes [0]https://smile.amazon.com/Earphones-Earbuds-Headphones-Premium-Compatible/dp/B07PT3R6TN/ref=sr_1_4?keywords=headphones&qid=1554964160&s=gateway&sr=8-4 https://smile.amazon.com/Earphones-Earbuds-Headphones-Premiu...