That, and the comparison was made against Zimmerman's normal, non-stressed voice. Using brand-new, un-vetted, just-released-to-market voice-analysis software - developed, marketed, and sold by the "expert" himself.

Wouldn't this be up to the jury whose voice it is screaming? The father of TM said it wasn't TM. The mother says it was. The father of GZ says it was him. There is a bunch of malarkey as to why Tracy said it wasn't TM. There is a witness who said he heard the one on the bottom screaming.

Common sense tells you TM had no reason to be screaming since he was on top beating GZ's head into the concrete.

I don't see the big deal in this.

Talking off the top of my head, and from memory....

Didn't the shonky analysis in effect claim the voice did not match the sample of GZ they used... that is all? They have no sample of TM. They are saying it's not GZ therefore it is TM?

THAT is about as shonky as "scientific" analysis gets.

"I took all of the screams and put those together, and cut out everything else," Owen says.
The software compared that audio to Zimmerman's voice. It returned a 48 percent match.

Voice comparison is not possible for the designated voices due to extreme stress and unsuitable voice quality

Critical listening and digital signal analyses further revealed that the screaming voice of the 911 call is of insufficient voice quality and duration to conduct a meaningful voice comparison with any other voice samples due to the screaming voice being: (1) produced under an extreme emotional state, (2) limited in the number of words and phrases uttered, (3) superimposed by other voices most of the time, and (4) distant, reverberant, and very low signal.

W6 recanted about hearing Zimmerman himself scream. He said something to the effect that he couldn't see who was doing the yelling but that common sense told him it was the guy on the bottom getting struck.

That, and the comparison was made against Zimmerman's normal, non-stressed voice. Using brand-new, un-vetted, just-released-to-market voice-analysis software - developed, marketed, and sold by the "expert" himself.

I thought the police took samples of GZ screaming over the police radio.

Wouldn't this be up to the jury whose voice it is screaming? The father of TM said it wasn't TM. The mother says it was. The father of GZ says it was him. There is a bunch of malarkey as to why Tracy said it wasn't TM. There is a witness who said he heard the one on the bottom screaming.

Common sense tells you TM had no reason to be screaming since he was on top beating GZ's head into the concrete.

I don't see the big deal in this.

W6 recanted about hearing Zimmerman himself scream. He said something to the effect that he couldn't see who was doing the yelling but that common sense told him it was the guy on the bottom getting struck.

that he couldn't see who was doing the yelling

W6 recanted about hearing Zimmerman himself scream. He said something to the effect that he couldn't see who was doing the yelling but that common sense told him it was the guy on the bottom getting struck.

It's not clear why prosecutors have subpoenaed the head of records at the jail where Zimmerman was locked up for several weeks

You mean "I listened to it and is sounds like a kid" isn't scientific?

For authentication of jail records to try and get them into evidence. Maybe recordings of Z's phone calls from jail?

In addition to the fact that the state of the law concerning expert voice identification was ambiguous, the expert testimony presented at the evidentiary hearing demonstrates that spectrographic analysis is—and was at the time of Drones's trial—of questionable scientific validity. Most notably, at the hearing, Koenig testified that there is no proven theoretical basis for the basic underlying premise that one person's voice is truly unique and therefore identifiable. He further stated that this has resulted in a precipitous drop in the number of expert practitioners over the past few decades, from fifty to sixty practitioners in the 1970's to roughly a dozen experts at the time of Drones's trial. While Cain testified that expert voice identification testimony has been used extensively in state and federal courts over the past thirty years, he also testified that he did not know if spectrographic evidence was widely accepted by the relevant scientific community. He also acknowledged that numerous factors—including a defendant's ability to disguise his own voice—could affect the reliability of expert analysis.

US v. Angleton, 269 F. Supp. 2d 892 - Dist. Court, SD Texas 2003 is only a trial court decision, but has an extensive discussion of the reliability of expert voice identification. The version I linked to also contains the amusing error: "The government presented Dr. Hirotaka Nakasone as a witness on the use and relability of the spectrographic methods of mice identification." I've always wished I could relably identify mice.

(For those who don't know, in the federal court system, the trial courts are called district courts, and the appellate courts are called circuit courts -- the opposite of Florida's court system.)

III. Conclusion
The testimony and evidence show that voice identification techniques using the aural spectrographic method are not widely accepted by the scientific community. The evidence and testimony show that there is great dispute among researchers and the few practitioners in the field over the accuracy and reliability of voice spectrographic analysis to determine the identity of recorded speakers. The evidence also shows that error rates for voice spectrographic techniques are unknown and vary widely depending on the conditions under which the analysis is made. The post-Daubert case law casts doubt on the reliability and admissibility of voice spectrograph analysis. The protocol Cain followed did not protect against several sources of error, further reducing the reliability of the voice spectrographic analysis conducted in this case. This court GRANTS the government's motion to exclude the testimony of Stephen Cain.