Re:The “432 Hz vs. 440 Hz” conspiracy theory
by schoen on Monday October 24, 2016 @10:19PM
(#12784753)
There are several different Clipper beeps:
* One beep - successfully paid fare
* Two beeps (different) - successfully paid fare, and you're about to run out of money on your card
* Two beeps (equal) - tagged off (e.g. on Caltrain or San Francisco Bay Ferry)
* Three beeps - read error or insufficient value
There might be others. Indeed, they've introduced a quieter "here is a Clipper reader" beep to help visually impaired people locate them: https://vimeo.com/183916243
* One beep - successfully paid fare
* Two beeps (different) - successfully paid fare, and you're about to run out of money on your card
* Two beeps (equal) - tagged off (e.g. on Caltrain or San Francisco Bay Ferry)
* Three beeps - read error or insufficient value
There might be others. Indeed, they've introduced a quieter "here is a Clipper reader" beep to help visually impaired people locate them: https://vimeo.com/183916243