Re: [Phys-L] new audio speakers

[Brian Whatcott <betwys1@sbcglobal.net>]

 "Using a 3D sensing module that locates the ears and directs ultrasonic waves, the SoundBeamer 1.0 creates small bubbles of 360-degree sound in the spaces where headphone speakers would normally go."

That's the blurb which implies a three  dimensional ear locator and a phased sound speaker array.The concept is more familiar when incorporated  in phased radar arrays which modify the phase of a output signal to steer the beam. This is rather difficult to do with low frequency sounds though, so  narrow ultrasonic beams modulated with an audio signal exploit the  non-linearity of the air path to provide the difference frequency as a sound wave.
Brian W(nitpicking mode on:  'Subsonic' implies frequencies lower than audible sounds, such as 10 Hz.)    On Friday, November 13, 2020, 12:53:35 PM CST, Roger Key <rogerk@csufresno.edu> wrote:  
 
 That looked familiar to me, so I went hunting.

At the 2019 AAPT Apparatus Competition, a similar device was shown. I have
a picture somewhere, but it's missing to me at the moment.

See page 20 of this PDF:

https://www.aapt.org/Contests/upload/AppCompSM19_images_booklet.pdf

LLAP

Roger Key
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On Fri, Nov 13, 2020 at 10:39 AM Roger Key <rogerk@csufresno.edu> wrote:

> Speculation:  Ultrasonic sounds arranged to produce beats that make the
> desired sounds, and those beats only happen at the location of the
> listener's ears, while everywhere else the sound is almost eliminated by
> destructive interference?  I find it difficult to imagine, but maybe
> possible?
>
> Very cool technology, however they do it.
>
>
> Roger Key
> Instructional Support
> 559-278-2728
> [web <http://www.fresnostate.edu/csm/physics/>][facebook
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>
> ------------------------------
>
>
> On Fri, Nov 13, 2020 at 10:17 AM Anthony Lapinski <alapinski@pds.org>
> wrote:
>
> > Hope everyone is doing well, feeling well, and teaching well in this new
> > reality.
> >
> > Speaking of new realities, I saw this yesterday on the news. Wireless
> > speakers and no earbuds needed! I was intrigued. How does this work? How
> > can this work? Subsonic waves decrease in frequency to the audible range
> > when conducting through bone/tissue? Interference phenomenon?
> >
> >
> > https://apnews.com/article/new-tech-device-sound-beaming-noveto-38327ae5fe116080a5eaf2374eb0f5c8
> >
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