Usually they cry out when you're in the vicinity, Ive just noticed that mine arent. Could it be because I'm running the Wilderness sounds mod? The pvssyr of the townfolk in towns I think has overidden the Strider bleat.

Did You check this http://www.gamesas.com/topic/1484920-voiceless-silt-strider-after-mod-addition/?hl=%2Bsilt+%2Bstrider#entry23275484?

Had this problem some time ago.

Scroll down to abots post. He found the solution.

Thanks I'll take a look.