STKWhistle — STKWhistle produces whistle sounds.


STKWhistle produces (police) whistle sounds. It uses a hybrid physical/spectral model of a police whistle (a la Cook).


asignal STKWhistle ifrequency, iamplitude, [kc1, kv1[, kc2, kv2[, kc3, kv3[, kc4, kv4[, kc5, kv5]]]]]


ifrequency -- Frequency of note played, in Hertz.

iamplitude -- Amplitude of note played (range 0-1).


kc1, kv1, kc2, kv2, kc3, kv3, kc4, kv4, kc5, kv5, kc6, kv6, kc7, kv7, kc8, kv8 -- Up to 8 optional k-rate controller pairs for the STK opcodes. Each controller pair consists of a controller number (kc) followed by a controller value (kv). The 5 controller numbers and values that work for STKWhistle are:

  • kc, kv -- 2, blowing frequency modulation.

  • kc, kv -- 4, noise gain.

  • kc, kv -- 11, fipple modulation frequency.

  • kc, kv -- 1, fipple modulation gain.

  • kc, kv -- 128, volume.

[Note] Note

The code for this opcode is taken directly from the Whistle class in the Synthesis Toolkit in C++ by Perry R. Cook and Gary P. Scavone. More on the STK classes can be found here:


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

Example 762. Example of the STKWhistle opcode.

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

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

instr 1

ifrq	=	p4
kblw	line	p5, p3, p6				;Blowing Frequency Modulation
kflp	=	p7					;Fipple Modulation Frequency

asig	STKWhistle cpspch(p4), 1, 4, 20, 11, kflp, 1, 100, 2, kblw, 128, 127
asig	=	asig*.7				;too loud
	outs asig, asig


i 1 0 .5 9.00 100 30 30
i 1 1 3  9.00 100  0 20
i 1 4.5 . 9.00 1  0 100 


Author: Michael Gogins (after Perry Cook)
Irreducible Productions
New York, NY

New in Csound version 5.11