I have a plastic one which works just as well as the lovely wooden one my mentor had. I think it would be difficult to stay in that position to count for a full minute - I have been using the pinard to find the FH (checking against mum's pulse) then using the sonicaid to let mum have a listen and count for a minute (so much easier as you can go straight to the slight impression left by the pinard!).

None of the RM's use the pinard regularly - got the impression they come out for the benefit of the students!