****************************
Main Group 45: FOF Synthesis
****************************


Sub Id  Contents

01      FOF Tutorial 
    1   minimum instrument
    2   LINSEG amplitude envelope
    3   exaggerated vibrato
    4   moving from granular texture to timbre
    5   octaviation coefficient
    6   striated formant frequency
    6B  smooth formant frequency
    6C  FM modulated formant frequency
    7   rise of granules
    8   middle decay of granules
    9   decay of granules
   10   duration and decay of granules
   11   rise and middle decay: band- and skirtwidth

33      Summed FOF Generators
    1   aaah...

------------------------------------------------------------ next

Overview

Designed in the first place for rich vocal imitation, and
developed from the CHANT program, the FOF unit generator
produces a complex, periodic signal with one spectral formant
region. 

FOF's model is closely related to the source/filter paradigm of
natural instruments and the voice: a complex source is
amplified by a complex resonator. On the other hand, FOF 
produces series of very short, often overlapping excitations,
that can be considered to be granules. (Clarke, J.M. 1988)

------------------------------------------------------------ next

Suggested Reading

Bennet, G. 1981.
"Singing Synthesis in Electronic Music."
In Research Aspects of Singing, ed. J. Sundberg.
Publication 33. Stockholm: Royal Swedish Academy of Music, pp. 34-50.

Bennet, Gerald and Xavier Rodet. 1989.
"Synthesis of the Singing Voice."
in Mathews, M.V. and J.R. Pierce, eds.1989. 
Current Directions in Computer Music Research. 
MIT press, pp. 19-44.

Clarke, J.M, P.D. Manning, R. Berry and A. Purvis. 1988. 
"VOCEL: New Implementations of the FOF Synthesis Method."
Proceedings of the 1988 International Computer Music Conference. 
San Francisco: International Computer Music Association.

Clarke, J.M. 1988.
"FOF Synthesis on the Atari ST."
in FOF Manual, Appendix 1. 
York, England: Composers' Desktop Project, pp. 8-14.

Clarke, J.M. 1989.
"An FOF Synthesis Tutorial."
in Csound Manual, Appendix 3. 
Available via anonymous ftp from cecelia.media.mit.edu:
pub/Csound/csbeta/csman.ps.Z of feb 5, 1993, pp. 114-117.

Rodet, X. 1984.
"Time-Domain Formant-Wave-Function Synthesis."
Computer Music Journal 8(3):9-14.

Rodet, X., Yves Potard, and Jean-Baptiste Barrire. 1984.
"The CHANT Project: From the Synthesis of the Singing Voice to
Synthesis in General."
Computer Music Journal 8(3):15-31.

Sundberg, J. 1975.
"Formant Technique in a Professional Female Singer."
Acustica 32:89-96.

Sundberg, J. 1978.
"Synthesis of Singing."
Swedish Journal of Musicology 60(1):107-112.


Sundberg, J. 1979.
"On Coupling between Vocal Tract and Voice Source."
Rapports IRCAM, Vol. 21. 

Sundberg, J. 1979.
"Chest Vibrations in Singers."
Rapports IRCAM, Vol. 22. 

Sundberg, J. 1987.
The Science of the Singing Voice.
Dekalb, IL: Northern Illinois University Press, 216 pp.

Zera, J., J. Gauffin and J. Sundberg. 1984.
Synthesis of Selected VCV-Syllables in Singing."
Proceedings of the 1984 International Computer Music Conference. 
San Francisco: International Computer Music Association.


------------------------------------------------------------ next


FOF Tutorial

Sub group 01 holds all of the FOF tutorial instruments. Please
refer to Appendix 4 of the Csound manual for a detailed
discussion of these instruments. (Vercoe 1993b: pp. 114-117)

Please note:
The FOF unit generator has been subject to changes in the last
years. In the FOF group below, we use the currently valid input
parameters, as described in the Csound manual of 1993. Earlier
versions of the Csound manual should not be used aside with
these instruments!

------------------------------------------------------------ next


45_01_1
additional parameters: none


This is the minimum FOF configuration with some ordinary
parameter values

(flowchart)
(.orc and .sco files)

------------------------------------------------------------ next


45_01_2
additional parameters: none

A simple amplitude envelope applied to FOF.


(flowchart)
(.orc and .sco files)


------------------------------------------------------------ next

45_01_3
additional parameters:


This design shows how to add an exaggerated vibrato to the
fundamental frequency.


(flowchart)
(.orc and .sco files)


------------------------------------------------------------ next


45_01_4
additional parameters:


The design on this page shows a transition from granular
texture to timbre, from pulse to pitch. This is achieved by
varying the fundamental frequency from 5 Hz to 200 Hz (see
below). Long duration of 10 sec is required.

(flowchart)
(.orc and .sco files)

------------------------------------------------------------ next

45_01_6B
additional parameters:


Smooth variation of the formant frequency at audio rate. 


(flowchart)
(.orc and .sco files)

------------------------------------------------------------ next

45_01_6C
additional parameters: 


FM modulation of the formant frequency at audio rate.

(flowchart)
(.orc and .sco files)

------------------------------------------------------------ next

45_01_7
additional parameters:


Variation of the rise parameter of the granules.


(flowchart)
(.orc and .sco files)

------------------------------------------------------------ next

45_01_8
additional parameters:

Variation of the middle decay of the granules. The rate of the
build-in exponential decay is controlled by kband. The bigger
kband the steeper the decay; zero means no decay.

(flowchart)
(.orc and .sco files)

------------------------------------------------------------ next

45_01_9
additional parameters:


Variation of the exponential decay of the granules. 


(flowchart)
(.orc and .sco files)

------------------------------------------------------------ next

45_01_10
additional parameters:


Variation of duration and exponential decay of successive
granules.

(flowchart)
(.orc and .sco files)


------------------------------------------------------------ next

45_01_11
additional parameters:


Variation of middle decay and rise of the granules, corre-
sponding to band- and skirtwidth in the spectral domain.

(flowchart)
(.orc and .sco files)

------------------------------------------------------------ next

45_33_1
additional parameters:

This instrument synthesizes the vocal [a] for a male person.
The four formant peaks (500, 850, 2500 and 3500 Hz) are
specified by four FOF generators. Each FOF generator runs at a
different amplitude. The result is summed. (Vercoe 1993:
testfiles/fof.orc)

(flowchart)
(.orc and .sco files)

