[BusyBox] How to turn speaker off under the busybox system?

[StF]

Hello everyone! =)

I've build the busybox system for my notebook. Everything works fine, except
speaker. When baterry has about 10% of it's capacity (and using it - can
work approx. 25 minutes), the notebook starts beeping, telling about low
battery event.
In Linux, I mean in other version of linux, I have used setterm with
"-blength 0" attribute and it works fine. But, here - no setterm ;)  Any
ideas how to do this in busybox-based system? Maybe some piece of code or
something?

Thanx in advance,
Pavel