Sound science

By The Newsroom

Published 18th Mar 2010, 20:00 BST

Updated 18th Mar 2010, 20:02 BST

There is an interfering variable in Chilton Inglis's thrifty experiment of sticking a finger in one ear (Letters, 17 March), namely that the internal throbbing, thus becoming audible, competes against external sounds.

Kathleen Manning, McVeagh Street, Huntley