Description

Audio output is a tone related to the shaking of a maraca or similar gourd instrument. The method is a physically inspired model developed from Perry Cook, but re-coded for Csound.

Syntax

ares shaker kamp, kfreq, kbeans, kdamp, ktimes [, idecay]

Initialization

idecay -- If present indicates for how long at the end of the note the shaker is to be damped. The default value is zero.

Performance

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

kamp -- Amplitude of note.

kfreq -- Frequency of note played.

kbeans -- The number of beans in the gourd. A value of 8 seems suitable.

kdamp -- The damping value of the shaker. Values of 0.98 to 1 seems suitable, with 0.99 a reasonable default.

ktimes -- Number of times shaken.

	Note
	The argument knum was redundant, so it was removed in version 3.49.

Examples

Here is an example of the shaker opcode. It uses the file shaker.csd.

<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
; Audio out   Audio in    No messages
-odac           -iadc     -d     ;;;RT audio I/O
; For Non-realtime ouput leave only the line below:
; -o shaker.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

; Initialize the global variables.
sr = 44100
kr = 4410
ksmps = 10
nchnls = 1

; Instrument #1
instr 1
kfreq	line p4, p3, 440
   a1 shaker 10000, kfreq, 8, 0.999, 100, 0
   out a1
endin


</CsInstruments>
<CsScore>

i 1 0 1 440
i 1 + 1 4000

e
</CsScore>
</CsoundSynthesizer>

Credits

New in Csound version 3.47

Fixed the example thanks to a message from Istvan Varga.