It’s important to remember that anything can be used as the carrier and modulator in a vocoder – it’s just that most people want to use speech as the modulator to achieve the classic robotic vocoder effect. These band pass filter signals are then passed onto the carrier wave where your final sound is created. The modulator takes your voice, finds the fundamental frequencies (important bits) of it, and converts them into levels of amplitude on a series of band pass filters (this is why some vocoders have different numbers of bands) – in general, the more bands available the more understandable your speech will be. The carrier is the sound you want to vocode through, and the modulator is your voice. A ‘carrier’ wave, and a ‘modulator’ input. So how does it all work?Ī vocoder needs two inputs to function properly. However, used properly within a song they can work well, and add a (now rather retro) techno-effect to a piece of music. They allow you to ‘talk like a robot’, which while fun, is often not musically useful. Vocoders are an instantly recognizable synthesizer sound, having been used in popular music since the 1960s.
