sr	=	44100
kr 	= 	4410
ksmps 	= 	10
nchnls	=	2

;*** Warning! This example is not intended to be heard, but only to visualize the generated signals 
;*** with a wave editor. Don't attempt to hear it, because very low frequencies could damage the speakers

	instr	1
k0	line	0,p3,1 ;modifies the envelope dinamically
kfreq	expon	.5,p3,15 ;modifies envelope repeat frequency
ktrig	metro	.5 ;forces the envelope to restart from the beginning

;ksig	lpshold	kfreq, ktrig, ktime0, kvalue0  [, ktime1, kvalue1, ... , ktimeN, kvalueN] 
k1	lpshold	kfreq,  0,  0,0, 10+k0*200,30000, 110-k0*100,10000, 30,3000, 30,10000, 30,0
;negative frequency produces backward envelope 
k2	lpshold	-kfreq, 0,  0,0, 10+k0*200,30000, 110-k0*100,10000, 30,3000, 30,10000, 30,0
a1	upsamp	k1
a2	upsamp	k2
	outs	a1,a2

	endin