sine 0.1 1
hold
regset zz 0

fmpair \
    [gensine [tabnew 8192]] \
    [biscale [regget 0] 100 600] \
    [param 1] \
    [param 1] \
    [biscale [regget 0] 0.1 2] \
    [param 0]

mul zz 0.5

dup; dup

bigverb zz zz 0.97 10000
drop
mul zz 0.1
dcblocker zz

add zz zz

wavout zz "siren.wav"

unhold [regget 0]

computes 10