On Wed, 26 Jul 2006 21:54:10 +0100, "Dave Plowman (News)"
wrote:

get a mechanic's stethoscope with a rigid probe connected to a diaphram.

How much are those?

Expensive! Mine came from the usual route (mil-surpus from Anchor)

You can improvise though. The screwdriver in the ear is effective, if
inconvenient in layout. You can make all sorts of lashups with two
tincans and a length of string, then work up from there.