Sonic fabric. That's the basis of these tie designs by Alyce Santoro. Sonic fabric is woven of 50% colored thread and 50% cassette tape, so if you were to run over one of these ties with a tape head you'd actually hear audible sounds. Garbled, jumbled sounds, but sounds nonetheless.
The ties are geared to New Yorkers as the audio tape is filled with recordings from on and under the streets of NYC, but clearly they can be enjoyed by anyone as the ties themselves are very crisp and stylish (and how often will you be listening to them anyway). They come in several colors and 3 styles (narrow, medium, and wide) for $90-$140.