gogobel — Audio output is a tone related to the striking of a cow bell or similar.


Audio output is a tone related to the striking of a cow bell or similar. The method is a physical model developed from Perry Cook, but re-coded for Csound.


ares gogobel kamp, kfreq, ihrd, ipos, imp, kvibf, kvamp, ivfn


ihrd -- the hardness of the stick used in the strike. A range of 0 to 1 is used. 0.5 is a suitable value.

ipos -- where the block is hit, in the range 0 to 1.

imp -- a table of the strike impulses. The file marmstk1.wav is a suitable function from measurements and can be loaded with a GEN01 table. It is also available at ftp://ftp.cs.bath.ac.uk/pub/dream/documentation/sounds/modelling/.

ivfn -- shape of vibrato, usually a sine table, created by a function.


A note is played on a cowbell-like instrument, with the arguments as below.

kamp -- Amplitude of note.

kfreq -- Frequency of note played.

kvibf -- frequency of vibrato in Hertz. Suggested range is 0 to 12

kvamp -- amplitude of the vibrato


Here is an example of the gogobel opcode. It uses the file gogobel.csd, and marmstk1.wav,

Example 343. Example of the gogobel opcode.

See the sections Real-time Audio and Command Line Flags for more information on using command line flags.

; Select audio/midi flags here according to platform
-odac     ;;;realtime audio out
;-iadc    ;;;uncomment -iadc if realtime audio input is needed too
; For Non-realtime ouput leave only the line below:
; -o gogobel.wav -W ;;; for file output any platform

sr = 44100
ksmps = 32
nchnls = 2
0dbfs  = 1

instr 1

   kfreq = 200
   ihrd = 0.5
   ipos = p4
   kvibf = 6.0
   kvamp = 0.3

asig gogobel .9, kfreq, ihrd, ipos, 1, 6.0, 0.3, 2
     outs asig, asig
;audio file
f 1 0 256 1 "marmstk1.wav" 0 0 0
;sine wave for the vibrato
f 2 0 128 10 1

i 1 0.5 0.5 0.01
i 1 + 0.5 0.561
i 1 + 0.5 0.9


Author: John ffitch (after Perry Cook)
University of Bath, Codemist Ltd.
Bath, UK

New in Csound version 3.47