> Sound.SC3.UGen.Help.viewSC3Help "Latch"
> Sound.SC3.UGen.DB.ugenSummary "Latch"

> import Sound.SC3.Monadic

> do {n <- whiteNoise AR
>    ;let {i = impulse AR 9 0
>         ;l = latch n i}
>     in audition (out 0 (blip AR (l * 400 + 500) 4 * 0.2))}

The above is just meant as example. LFNoise0 is a faster way to
generate random steps :
> do {n <- lfNoise0 KR 9
>    ;audition (out 0 (blip AR (n * 400 + 500) 4 * 0.2))}

http://create.ucsb.edu/pipermail/sc-users/2006-December/029991.html
> do {n0 <- lfNoise2 KR 8
>    ;n1 <- lfNoise2 KR 3
>    ;let {s = blip AR (n0 * 200 + 300) (n1 * 10 + 20)
>         ;x = mouseX KR 1000 (sampleRate * 0.1) Exponential 0.1}
>     in audition (out 0 (latch s (impulse AR x 0)))}