Andy wrote: > >If it can be heard, it can be recorded. > For now, yes. Just connect a wire from the headphone output of a boombox to the audio in on your computer's soundcard, and use the recording program of your choice.
But the next step is encoding a subsonic audio signal into the recording that a cd burner would interpret as a command to not record. The only thing required for that is for someone to decide on a standard signal to do that, and a chip in all cd burners (or a piece of code in all recording software) to listen for that signal. Existing equipment would probably not be affected, just like really old VCRs ignore copy protection signals on video tapes because they don't have the chip that kicks in the color fluctuations or other effects of copy protection. By the way, subsonic would work but supersonic wouldn't, at least not with current CD sampling rates. At 44,100 samples per second for stereo audio, the highest frequency a CD can contain is 22,050 Hertz. Some people can hear that high (the generic standard range given for human hearing is 20 Hz to 20,000 Hz). A subsonic signal would probably be put in the range of 10 Hz or below to make sure it wouldn't affect the audio quality of the disk but would still be well below normal human hearing range. If the current method affects audio quality, it's probably adding "noise" directly to the digital signal, which would definitely affect the output. That would be similar to digital watermarks used on some images, where they change pixels in an image file in a specific way that allows a program to trace it back to the originator of the file, for a sacrifice of image quality (small but usually noticeable). Reggie Bautista _________________________________________________________________ Join the world�s largest e-mail service with MSN Hotmail. http://www.hotmail.com
