The ability to detect man-made interference is not much use unless the source can be located, however.

ECONOMIST: GPS jamming

This unusually long potentiometer shaft allows the signal path between the audio source and the potentiometer to be kept very short, thus preventing possible interference of the signal.

ENGADGET: Sennheiser unveils HDVA 600 analog headphone amp, asks for $1,600

Unlike earlier solutions -- like Eugene Polley's "Flashmatic" remote -- Robert's remote wasn't prone to interference, didn't require a wire, and, unlike current remotes, didn't require a power source.

ENGADGET: Robert Adler, co-inventor of the TV remote, passes away