Famous modular synthesizer manufacturers included Buchla & Associates, Moog Music, ARP Instruments, Inc., Serge Modular Music Systems, and Electronic Music Studios. Moog established standards recognized worldwide for control interfacing on analog synthesizers, using an exponential 1-volt-per-octave pitch control and a separate pulse triggering signal. These control signals were routed using the same types of connectors and cables that were used for routing the synthesized sound signals. A specialized form of analog synthesizer is the analog vocoder, based on equipment developed for speech synthesis. Vocoders are often used to make a sound that resembles a musical instrument talking or singing.