This procedure is good up to the point where it relies on ear "A" being comparable to ear "B". My hearing one side has quite different characteristics than the other side. Gordon, KA2NLM No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: 269.13.30/1025 - Release Date: 9/23/2007 1:53 PM