Favis220c

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Overview: For my 220C project, I am making vocoder renditions of choral music. The vocoder takes spectral qualities of the human voice and translates them to an instrument, creating what seems to be a "talking instrument" or "robot voice." Over the course of this project I aim to examine the effects of vibrato, pitch, vowels, and spectrum in the dry signal on the vocoded sound and discover how choral music translates to vocoded vocals.

I will be vocoding three choral pieces: Maurice Duruflé's "Ubi Caritas," Wolfgang Mozart's "Lacrimosa," and Eric Whitacre's "Lux Aurumque."


Vocoder: I made a basic vocoder in Max MSP, but I am not satisfied with the quality of sound and annunciation of vowels/consonants. Since the goal of the project is to examine the effect of dry parameters on vocoded sound, the origin/originality of the vocoder is not necessarily a priority to me. I may end up toying with an already-made vocoder in Logic for the purposes of efficiency, timbre, and sound quality.


Methodology: One singer is assigned to each voice for each song. Every song has bass, tenor, alto, and soprano lines, and some lines have multiple voices per line. The group will sing together during the recording sessions, but each singer will have an individual microphone placed closely to his/her mouth to isolate his/her voice from the group. The goal is to allow singers to blend during the piece while still recording the voices separately for individual vocoding.

The following singers have generously agreed to record vocals for my project:


Ubi Caritas

Bass: Joel Chapman

Bass: Evan Gitterman

Tenor: Andrew Forsyth

Tenor: Will Watson

Alto: Laura Austin

Soprano: Mia Farinelli


Lux Aurumque

Bass: Joel Chapman

Bass: Evan Gitterman

Tenor: Andrew Forsyth

Tenor: Will Watson

Alto: Laura Austin

Alto: Michelle Jia

Soprano: Mia Farinelli

Soprano: Grace Laboy


Lacrimosa

Bass: Joel Chapman

Tenor: Andrew Forsyth

Alto: Laura Austin

Soprano: Grace Laboy

Piano: Nayantara Jain


Rehearsals and Testing: We held two rehearsals for each piece before recording. Both sessions went very swiftly because the singers sight-read each piece exceptionally well. During the rehearsals, I recorded some dry samples from Andrew Forsyth, the tenor voice. I had him sing phrases with and without vibrato. I also had him sing a short phrase (from Ubi Caritas) all on one note and then another take on another note. After vocoding each sample, I noticed the following:

1) Vibrato creates a nice spectral modulation in the vocoded voice. The amplitude and high frequencies flutter and add a pleasant human quality to an otherwise robotic voice.

2) When a vocoded note does not match the sung note from the dry sample, the formant of the vocoded voice is altered. Formant of the vocoded sample does not match that of the dry sample, and the vocoded sample sounds nasal as a result.

3) Consonants are well defined by the vocoder. Therefore, it is important to sample experienced singers who know how to sing consonants in traditional choral pieces (rolled r's, short s's, etc…).


Plan for Voice Vocoding: I will go through each vocal track and play each part's appropriate notes on the keyboard vocoder. This may be difficult and tedious, but I can use MIDI in Logic to edit/split/move notes according to the rhythm of the individual voices. Choosing good reverb will also be essential for blending and authenticity.

Voice Vocoding Process: