Agreed Richard. Like this expert:

http://legalinsurrection.com/2013/06/zimmerman-case-dr-hirotaka-nakasone-fbi-and

Why didn't the judge allow the tape to be heard in court and then admit the testimony of someone with the expertise to establish that the science simply isn't there to properly identify the screams? Then the judge could have disallowed all biased testimony as to whose voice it was.

Think about it. Here, sitting in the courtroom you have two parents who list their 17 year old son. Every night they go home to their tv and listen to all the talking heads say over and over how the screams on the are the "most crucial piece of evidence." Believing their son was the victim, It had to be painful enough for them to have to defend that the screaming for help was their son, for Trayvon's father to be second guessed in court because he told police he didn't know whether it was Trayvon's voice (it was so wrong for police to deal with a parent in shock this way), but then a veritable troupe of Zimmerman supporters saying, "Yes, that's Georgie" etc. All that could have been avoided. All of was useless testimony, except for the defense who used it to their advantage by keeping the jury focused on the last 3 seconds of the encounter instead of the "most crucial" minutes that led up to it. Not to mention the days, weeks, months, and years that led up to it in the life of George Zimmerman. The following article gives insight into how he eventually killed somebody:

http://www.tampabay.com/news/humaninterest/trayvon-martins-killing-shatters-safe