A search for "Hypersonic Sound" on the USPTO dite came up with a patent owned (assigned) to the Xerox corporation, invented by Biegelsen; David K. (Portola Valley, CA.)

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.htm&r=14&p=1&f=G&l=50&d=PTXT&S1=%22hypersonic+sound%22&OS=%22hypersonic+sound%22&RS=%22hypersonic+sound%22

Scroll down and look at "References Cited" (Referenced By) and none other than patent #5889870 comes up,

"Acoustic heterodyne device and method"

Inventors: Norris; Elwood G. (Poway, CA)

http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5889870

Additionally, the patent for a "Directional speaker for portable electronic device"
Inventors: Cheung; Kwok Wai (Hong Kong, HK), Tong; Peter P. (Mountain View, CA), Thomas; C. Douglass (Campbell, CA)
Assignee: IpVenture, Inc. (Los Altos, CA)

again cites Norris in "Ear mounted RF receiver"
Inventors: Norris; Elwood G. (Poway, CA)
Assignee: American Technology Corporation (Poway, CA)

http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F5313663

And, as for the first patent I referenced, there is a common element between Xerox and e-Digital, according to 98 Observer... http://smallcapinvesto.agoracom.com/ir/edigital/forums/discussion/topics/450312-one-year-ago-and-three-months-after-that/messages/1465467

I wonder if there is any proximate connection between e-Digital as a company and this new Hypersonic Sound....maybe we'll find out this week.

Lurk mode back on until we see some more big news...