(FM, Frequency Modulation) A process of translating baseband information to a higher frequency; carrier frequency, so more information can fit into a transmitted or recorded space. The video and two analog audio channels are FM modulated on to their own carriers so that they will all fit on the disc. The process: The two input signals to an FM modulator are the baseband signal (video or one of two audio channels) and the carrier frequency (a constant amplitude and constant frequency signal). The frequency of the carrier is modulated (changed; increased and decreased about its zero state) by the amplitude of the baseband signal. A large amplitude signal will cause a large shift in the carrier frequency, etc. The rate of shift (how fast the carrier is changed from one frequency to another) is determined by the frequency of the baseband information. The FM system is often preferred to AM (Amplitude Modulation) as a carrier of baseband information because of its greater noise immunity.