Embedding Data Signals In White Noise 239
Anemophilous Coward writes "ZDNet has the following article which describes a company that 'has devised a method for sending wireless signals over ordinary audio speakers so that humans can't hear them. With this same technology, radio stations can unobtrusively transmit ads, Web site URLs, or information about music and artists to in-car cell phones.'" Here is some further reading about the company, Intrasonics.
So? (Score:4, Insightful)
Let me guess, by using the correlation of psuedo-random noise sequences summed with the signal.
-Chris
Depressing lack of imagination (Score:3, Insightful)
I find it sad that everytime a new technology such as this is developed, the first instinct of the marketing people tasked with selling it is to figure out a way to make it push ads into my perceptual environment, almost guaranteeing an initial cynical reaction..
Re:MP3s and Watermarking (Score:5, Insightful)
Depending on how this is implemented, lossy audo compression techniques used in MP3 or OGG may strip the info. One of the reasons that these formats can get such good compression rates is that they strip a lot of the acoustic information that people can't hear -- which is exactly where these guys are looking to put their signals.
My guess is that someone could come up with a lower bandwidth approach that would remain in the signal after compression. But they'd probably have to tailor their approach to the specific algorithms in a particular MP3/OGG encoder. If someone used a different encoder or the encoder was upgraded, a new solution would need to be created.
Of course if this technology is primarily used for advertising, then people would want to strip the information. If, on the other hand, the data were truly useful to users, there might be an effort to preserve it after compression.
cell phone battery life (Score:1, Insightful)
and the DSP processor (normally used for voice compression in GSM phones) will be on all the time.
A couple milliamps extra current will take hours off the standby time.
White is colored dots anyway (Score:3, Insightful)
Embedding signals leads to noise with cumulants different from zero for different times, and thus the noise is not white anymore, it becomes colored.
Your display probably isn't true white either; it's made of tiny red, green, and blue dots. This article is about perceptually hiding information in audio that humans hear as "white" but that machines can pick apart. It's steganography.
Better use of technology (Score:5, Insightful)
Song Titles - How about ID tags so you can actually see the exact title of the song your listening to? You can keep a 10 song list like caller ID. You can see the last few songs you listened to. For advertisers you would keep one text line scrolling on the display.
Second Audio Channel - A secondary program at AM quality on an FM station. Kinda like how HDTV can have up to 6 lower quality channels.
Radio for the Death - Close Captioning of radio lyrics. 'Nuff said.
Emergency Broadcast Technolgy - Give both a readable text warning and GPS cordinates of pending danger.
Exact Station Date and Time - Isn't that what you really want half the time you turn on the radio anyway.
Weather and News Broadcasts - Get the local or national news in an instant.
Automatic Request line # - Never have to listen for those damn # to call while your driving.
Possible interactivity - Broadcast a survey to a cellphone, you log your answers, and then you transmit your results.