https://www.bloomberg.com/news/articles/2018-02-02/here-s-why-alexa-won-t-l=
ight-up-during-amazon-s-super-bowl-ad
"The second tactic describes how a commercial itself could transmit an inau=
dible acoustic signal to tell Alexa to ignore its wake word."





-----Original Message-----
>From: Harold Hallikainen <harold@mai.hallikainen.org>
>Sent: Feb 2, 2018 12:39 PM
>To: Pic List <piclist@mit.edu>
>Subject: [EE] Spread Spectrum Audio Watermarking
>
>I'm looking at sending some extremely low speed data under audio to
>identify the audio. The receiver would be an Android device with internal
>microphone. I'm thinking of using direct sequence spread spectrum with the
>level being substantially below the audio so it would appear to be very
>low level noise. But, my experience with spread spectrum is extremely
>limited. I'd appreciate any pointers to information on it, especially at
>audio frequencies, and any open source projects on it.
>
>THANKS!
>
>Harold
>
>
>
>--=20
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