Audio Effects – Vocoder and Auto-tune

Alright, thanks for coming back for my next installmentThis results in a series of numbers representing these
in this article series concerning audio effects. In themodified frequencies at any particular time as the user
past few weeks we have covered quite a fewspeaks. To recreate speech, the vocoder simply
commonly used effects, such as reverb, delay, flange,reverses the process, creating the fundamental
and compression. These effects all have wide scopesfrequency in an oscillator, then passing it through a
of usage, and are probably used on a daily basis instage that filters the frequency content based on the
most modern recording studios, on a wide range oforiginally recorded series of numbers. For musical
different musical styles. We were discussing the basicapplications, a source of musical sounds (such as a
functionality of each effect, leaving you to decide ifguitar) is used as the carrier, instead of extracting the
and how you would end up using it in your ownfundamental frequency. The vocoder is famous for
production process.creating robotic sounding voices, and has been used in
Today we’ll be moving on to a couple of otherfilm to create; surprisingly, robot voices.
types of effects, which are probably less used thatAuto-Tune
the others we’ve talked about. Don’t let thatAuto-Tune is used for correcting pitch in vocal and
fact deter you from reading any further, as these twoinstrumental performances. It works by employing
effects; vocoder and auto-tune, are both very flexibledigital signal processing algorithms (many which are
and powerful tools for you to add to your studiodrawn from the geophysical industry) to continuously
arsenal. So, please strap on your learning cap anddetect the pitch of aperiodic input signal and changes it
follow me.to a desired pitch. The harmonization is intended to
Vocoderincrease the musical quality of a vocal track without
The vocoder (its name being derived from “voicerevealing the singing as processed. This works well in
encoder”) is a speech analyzer and speecha studio environment to correct the performance of
synthesizer. It was originally created for use as avocalists and musicians, after they have recorded their
speech coder for the telecommunications industry intakes. It has also been widely used with extreme
the 1930s. It was used for secure radio communication,parameter values to create a distinct electronic vocal
where voice has to be digitized, encrypted and thensound.
transmitted on a narrow, voice-bandwidth channel. TheThis wraps up the 5th installment in the DiskFaktory
way that the vocoder works is that is finds the basicMastering article series on audio effects. Today we
carrier wave that the human voice produces. Thiscovered a couple of the more fun to work with
carrier wave is at the fundamental frequency (theeffects, in my opinion. I myself have learned quite a bit
lowest frequency in a harmonic series). Is is thenwriting today’s article, and I hope you feel the same
measured how its spectral characteristics areway. Now we’re much better prepared to create
changed over time by recording someone speaking.a symphony of robot voices.