Hey I'm having some issues in trying to find books on using a vocoder which blows. Found plenty of books on sound design and synthesis so I can't understand why I can't find books vocoders. Somebody please help!!!
The specific manual of the vocoder that you're using.
The overall idea of a vocoder is simple. In laymans terms:
You have two audio inputs: the source and the modulator.
The vocoder is a bunch of bandpass filters with envelope followers on each one of the filter bands. The envelope followers listen to the modulator input at each filter band, i.e. the gains of each filter band follow the constantly varying spectra of the modulator signal. The behavior and sensitivity of the envelope followers is usually adjustable and there may also be other parameters, like the count of the filter bands (higher count = clearer, smoother sound, lower count = cruder, synthetic sound).
The source signal is fed through this filter array. It becomes out modulated or "vocoded" by the modulator that controls the filter array.
Welcome to SSD.
Probably many of those books have sections on vocoding. What level of information are you trying to find? Are you looking for info on basic use or do you already know the basics and are looking for more detailed info?
For basic music tech information Sound on Sound is a good source for general, well written articles. Here's an example:
Searching around you should find plenty of these. SOS have written many more specific articles on using the vocoders bundled with most DAW's.
Is this the sort of thing you're after? Beyond that it's vocoder design and build, how analog and digital vocoders work at component/DSP level.
It is not clear if you want a book on the theory/implementation of vocoding or if you want one that covers using a vocoder for sound design. If you clarify this you will probably get more responses.
Designing Sound by Andy Farnell covers both briefly.
As previous post says, its bunch of filters with envelope followers modulating the carrier... but remember if there is no content on that specific region of the carrier where the modulation is driving the amplitude envelope then there won't be any vocodding...what you need to know is if the spectral content of the modulator, which are overtones, have to match the carriers spectral harmonic structure and stay intact and synched at all times, by having the same pitch bend behavior...also carrier can be really crushed with a limiter to fill in the modulators shape driven off the envelope following, amp modulated filters that are lined up on the carrier signal...I think the cleanest, neatest way of vocodding audio is where you take audio and convert it into image with image lines "harmor" then multiply it with another audio-image in photoshop, finally converting back to audio with harmor...harmor as a vocoder