Experts: Cries in 911 call unintelligible
Source: Orlando Sentinel
SANFORD Two defense experts testified Saturday that screams heard in the background of a 911 call just before Trayvon Martin was shot are unintelligible and that there is no valid scientific way tell who was crying for help.
"Speech is not like fingerprints," said George Doddington, an electrical engineer who specializes in speaker-recognition systems. "Speech is not like DNA." . . .
On Saturday, Doddington and a second defense expert, John Peter French, said the methods of the state's two experts were so fundamentally flawed, it was laughable. . . .
No respectable scientist would try to compare a recording of someone speaking normally to one of someone screaming and attempt to make an identification, he added.
Read more: http://www.orlandosentinel.com/news/local/trayvon-martin/os-george-zimmerman-trial-ruling-audio-20130608,0,5224051.story
Cooley Hurd
(26,877 posts)grok
(550 posts)as we do to ourselves. hearing though our bones instead of just eardrums. Add the rarity of yelling like a little girl in fear and the embarrassment and you get the picture.
That is if you WANT to see it.
http://www.scientificamerican.com/article.cfm?id=why-does-my-voice-sound-different
http://mentalfloss.com/article/12796/why-do-our-voices-sound-different-us-other-people
--Quote
For many of us, there are few things more painful than hearing a recording of our own voices. They dont sound like we think they should. Theyre tinnier, higher and just not right. The tape (or mp3) doesnt lie, though, and the way we think we sound isnt how we really sound to everyone else. This is a cruel trick that happens because of the ways that sounds can travel to our inner ear.
--Unquote
Personally i think i sound like a young James Earl Jones..
In reality, my voice is more akin to Gomer Pyle(Jim Nabors)
7962
(11,841 posts)Ive always HATED hearing a recording of my voice!
Jamastiene
(38,187 posts)One band I was in wanted me to sing backing vocals. I still think any recordings we did back then sounded terrible with me singing. It sounded so much better when I just played guitar and the other girl sang backup. She could sing, but did not want to be in a band any more.
crim son
(27,462 posts)What's new?
grok
(550 posts)And people choosing to use bad science because they like the results. BUt that is understandable. Tarot card readers make a great living telling people what they want to believe.
Respected experts with the years, the court experience, and degrees in related fields vs. Self proclaimed experts, using outdated or unproven technologies they don't even understand. Owen alone gets over a thousand in commission per sale of EasyVoice.
I didn't personally hear the second "expert" from yesterday but i did hear the first. Ted Owen. And it was very telling.
What he said he did to get the result he wanted is that since he didn't have enough data he just he just duplicated what little he had 5 times to get to the BARE MINIMUM to analyze!.. That's just not done in any meaningful scientific analysis of any sort! NOt to mention how that distorts data by adding unforseen harmonics!(ok, im a fan of fourier analysis)
That's actually worse than a single paragraph from a short tale and trying to predict the entire story from it.
yardwork
(61,418 posts)The jury will hear the 911 call and reach their own conclusions.
After listening to the 911 call, I have no doubt that it is the sound of a teenager screaming in fear for his life.
grok
(550 posts)that's really a level playing field..
pacalo
(24,721 posts)grok
(550 posts)The defense experts has three experts.
Defense Expert #1, Dr. Hirotaka Nakasone, PhD: A senior scientist with a 17-year career with the Federal Bureau of Investigation, currently the Head of the Bureaus Voice Recognition Program, and the Head of the international working group establishing the first formal scientific standards for speech recognition and speaker identification. On an additional note, Nakasone was the FIRST person the state called to analyse the screams. They didn't like his conclusions obviously since now they have to scrape the bottom of the barrel.
Defense Expert #2, Dr. J.P. (Peter) French, PhD: Dr. French earned his PhD in the analyses of recorded conversations, he is the Director of J.P. French Associates, the United Kingdoms longest established independent forensic laboratory specializing in the analysis of speech, audio, and language with 6 full-time scientific staff, and a Professor in the Department of Language and Linguistic Science, University of York. TESTIFIES MONDAY MORNING.
Defense Expert #3, Dr. George Doddington, PhD: Dr. Doddington conducted his doctoral thesis on speaker recognition, and since 1970 he has been leading the development and evaluation of speech recognition and speaker identification technologies and methodologies at a wide variety of top-level institutions, including Texas Instruments, the Defense Advanced Research Projects Agency (DARPA), the National Security Agency (NSA), and currently at the National Institute for Standards and Technology (NIST). Interestingly, he was deeply involved in the development of the voice recognition technology used in the F-16 fighter aircraft.
Now lets check out what the prosecution has to offer....
State Expert #1, Tom Owens: A one-man audio forensics operation whose highest academic degree is a BA in History, who has no formal academic training in speech recognition or speaker identification, whose standards for analysis are self-written and in any case subject to self-violation in order to ensure a finding, who uses as his primary speech analysis tool a computerized biometric system in which he has a substantial financial stake, and which in any case he has used for less than two years and tested about as an expert witness only once before.
State Expert #2, Dr. Alan Reich, PhD: A long-retired college professor with an avocational interest in speech recognition and identification who manages to hear words and phrases in audio recordings that cannot be heard by world-leading experts in the field, much less by layman. On another note, I have to give him a bit of respect because he at least admitted under oath that his opinion is no real proof. A man long past his prime if you bothered to listen to his testimony. To put it mildly.
Schooled....
pacalo
(24,721 posts)than he would be to the prosecution:
He said because the screaming voice was affected by distress or emotion, there was no way to compare it to "reasonable, natural speech and come up with correct answers."
"The screaming was not normal - it was pretty much uttered by someone who was facing probably imminent threat of death," he said. "Very difficult to analyze."
http://www.cbsnews.com/8301-504083_162-57588238-504083/george-zimmerman-update-audio-expert-testifies-accused-killer-zimmerman-is-likely-not-the-person-screaming-in-911-call/
As for Tom Owen, he is an "expert in voice identification":
(...)
... He only compared Zimmerman's voice to the 911 calls because he didn't have a voice sample for Martin at the time.
"The screams don't match at all," Owen said. "That's what tells me the screams aren't George Zimmerman."
Owen said that in general, it was much easier to make a positive elimination than an identification. On cross-examination, however, he said that the amount of screaming was enough to definitively rule out George Zimmerman.
"I didn't make a positive identification or elimination in this case," Owen said. "I made a probable elimination it was not George Zimmerman making the screams."
http://www.cbsnews.com/8301-504083_162-57588238-504083/george-zimmerman-update-audio-expert-testifies-accused-killer-zimmerman-is-likely-not-the-person-screaming-in-911-call/
(Btw, it's the usual practice at DU to cite your sources.)
grok
(550 posts)or statements you just posted. Only your conclusions.
As far as links regarding the Audio analysis issue testimony,
I actually provided NINE links to different items and documents in this thread alone. So THERE!
Here is another one! of the testimony. IIt's all there anyway. Defense and Prosecution did a good job of squeezing everything relevant out of the "experts".
http://www.hlntv.com/article/2013/06/07/george-zimmerman-trayvon-martin-911-call-hearing
They have been covering this testimony in it's entirety. While not an official transcript, it's pretty complete. Both questions and answers are covered. Not skewed one way in the other in the coverage. On the other hand, HLN TV opinion is skewed towards the prosecution. Almost completely devoid of inconvenient facts.
Think you would like that.
secondwind
(16,903 posts)Response to secondwind (Reply #16)
grok This message was self-deleted by its author.
Vattel
(9,289 posts)if what they have to say doesn't meet the relevant standards for "expert testimony."
yardwork
(61,418 posts)that claim that the prosecution's experts don't meet relevant standards.
In other words, both sides are bringing their experts, and each side will attempt to undermine the other side's experts.
grok
(550 posts)Standards are what keep people from getting railroaded and planes from crashing all the time.
There are actually two relevant standards here. the Frye and Daubert.
Fry is the really strict standard and there is now way the prosecution's witnesses will hold up in any appeal.
Daubert is much laxer and is coming into vogue.
What is ironic and hilarious is that Florida will discard the Frye standard and go Daubert in July. If the prosecution had not protested the delay the defense wanted, they might actually have gotten their witnesses to matter.
http://en.wikipedia.org/wiki/Frye_standard
Vattel
(9,289 posts)If the judge is not an idiot or a coward, the defense "expert" testimony will be excluded.
freshwest
(53,661 posts)Call me a stickler for logic or self-defense, but Z had a vehicle, and a gun. There is a difference in power right there.
Z was safe, in his vehicle, and was told to not confront TM. He took it on himself to do that. I would not have done that.
It would be one thing if I saw TM assaulting someone, that would require action. That is not what was happening.
I don't care if he says he was afraid of TM after getting out of that vehicle, because it's not logical.
I just keep getting back to that. He could have been safe where he was. He chose not to be and engaged.
He is responsible for everything that followed after making that choice. Everything, to himself, to TM, everything.
Jail. Prison. Whatever.
Am I being unfair or cold?
I don't think so. Open and shut.
Good to see you back, yardwork.
You can't chase someone down in the hopes they'll give you the chance to "defend yourself".
What never seems to come up with Zimmerman supporters that insist Z had a right to stand his ground is that TM had just as much right to stand HIS when some random dude was following him around. Or at least they'll never admit to why they don't think he had a right to defend himself.
KansDem
(28,498 posts)The SYG guy had the script down pat. Unfortunately for him, he was a bad actor...
yardwork
(61,418 posts)The only way to fashion a self-defense rationale for an armed man who shot to death an unarmed teenager is to recognize why Zimmerman chased Trayvon. Zimmerman would not have been suspicious of a middle-aged man in a suit. Zimmerman would not have chased an elderly woman through the neighborhood. If Trayvon had been wearing an Izod shirt and Dockers then Zimmerman would not have chased and shot him. In fact, Zimmerman probably would have given him a ride home through the rain.
The only reason Trayvon Martin is dead is because Zimmerman was afraid of him from the moment that he saw him. Zimmerman was afraid of Trayvon because Zimmerman saw a black teenage boy in a hoodie in "his" neighborhood and Zimmerman gave into race and class stereotypes and decided that that meant that Trayvon was a criminal, one deserving of being chased and shot. That's the only way to understand what happened that night.
JustAnotherGen
(31,683 posts)Myrina
(12,296 posts)It really IS as simple as that.
Zimmerman could have listened to 9-1-1 instructions and just went the fuck home.
Or followed Martin while staying IN HIS TRUCK.
There was no reason on Earth he had to get out of the truck & confront Martin. None.
grok
(550 posts)afterall, only a boy could make a such a pitiful cowardly scream eh?
or
or
for reference...
http://abcnews.go.com/GMA/video/trayvon-martin-case-voice-recording-emerges-lawyers-ready-19346403
Actually in normal speech, Trayvon's voice just might be deeper than George's..
pacalo
(24,721 posts)He apparently feels threatened without being able to carry a gun on his person. It gives him, the self-appointed neighborhood watchman, a big dose of courage to go out looking for an opportunity to exercise authority over others. It makes him feel bold enough to ignore the 911 dispatcher's logical advice to get back in his car (meaning, "go home & do not get involved" ; having a gun in his waistband & the "stand your ground" law to back him up, he's determined to push his way into the situation.
Having killed a teenager, he hires bodyguards that he cannot afford (ask Mrs. Zimmerman ) for protection.
Just look at Zimmerman's eyes in these pictures. He's a coward. He has forever lost his peace of mind due to his very bad decision.
Those screams sounded like a young person who saw a gun & was pleading for help. The coward had a gun, with no reason to yell for someone to watch him squeeze the trigger.
tomm2thumbs
(13,297 posts)When the expert says 'No respectable scientist would try to compare a recording of someone speaking normally to one of someone screaming and attempt to make an identification...'
they only need to discern if the sound represents one or the other - between the only 2 people involved
that makes things a bit different
grok
(550 posts)that Bugs Bunny isn't actually Mel Blanc...
Igel
(35,197 posts)You look at details when you examine how somebody speaks. The details of consonant formation. How their vowels are formed. How they transition from one to the other or let one influence the other. You compare how high and low frequences balance--you look at the sound spectrum and how energy's converted to sound waves.
Now consider the data.
It was produced by somebody using abnormal means. Consonants and vowels are distorted from the sample taken for comparison. Spectral tilt would be awesome. And not normal for either speaker.
It was heard dozens of yards away from the source of the sound. Versus collected inches away from the source of the sound--the person's vocal tract and buccal cavity. High frequencies tend to dissipate more quickly than lower pitches, making for a loss of detail and a change in the balance of high/low frequencies.
It was heard through glass. Which would have deadened high frequencies more than low frequencies.
It was picked up by a microphone that crucially relies on the capacity of the human ear to *reconstruct* low frequencies given high frequencies.
Then it was recorded by a 911 recording/backup. I've transcribed from those. they're scratchy and nasty recordings. Not exactly hi-fi. And nowhere near the fidelity used by most phoneticians and acousticians.
Then that snippet of data was replicated to provide enough *raw data*. That's rather like saying we don't have enough of a statistical sample to be reliable--you have 10 +/- 3. So let's just multiply it by 10 and take that number, 100, as the original sample size and say that's +/- 3. You can't do that. It violates the assumptions needed for the analysis.
Don't know what importance this has in the trial. Haven't followed it. Don't much care. I'm more interested in the linguistics and acoustics than in the legal repercussions.
The data's crap. What you get out of it is crap. It's easy to get phonetic analysis software. It's easy to follow the instructions. Understanding *when* the instructions apply, that requires understanding.
There are just too many variables here. Theres no way with all the noise etc. I heard it. Of course, there is probably a way to squelch some of the noise, but i dont see the science like blood or DNA. Like the tapes that the CIA would say are "believed" to be Osama. I dont think "believed" to be should be admissible in court.
pacalo
(24,721 posts)that he's not expected to testify, that scream needs to be heard by the jury -- even if no audio-expert analysis is allowed to be heard. Let the jury decide if the scream came from a young person who was facing the barrel of a gun or if it came from the shooter who wanted witnesses to see him squeeze the trigger.
grok
(550 posts)the scream that is for the past year? Should have it just right by now.
Oh yea. he WILL testify.
And let the jury decide after hearing both.
Agreed..
yardwork
(61,418 posts)After Zimmerman, armed with gun, stalked Trayvon Martin through the neighborhood, then according to Florida's Stand Your Ground laws, Trayvon was the one with the right to turn around and defend himself, even if it meant assaulting Zimmerman.
Don't you see that it doesn't matter whether Trayvon eventually assaulted Zimmerman or not? Zimmerman became an aggressor when he followed Trayvon while holding a gun.
grok
(550 posts)that he can punch out any paparazzi with impunity.
Hey, let's beat up any mall "cop" that thinks we are shoplifting and follows us! We got rights!!!
That being said, you do have a point there.*Perhaps* Martin could have applied the SYG law had he lived and was arrested after crippling Zimmerman with a brain hemorrhage. .
Only thing is thing it applies even more to Zimmerman. And he is the one alive to take advantage of SYG.
yardwork
(61,418 posts)What brain hemorrhage is this?
grok
(550 posts)i've had two people in my life die this way. It actually doesn't always take much.
My elderly aunt who rolled off her very low cot. onto a thin carpet. Maybe a bone density issue. I actually got questioned on that by a detective. She was visiting me.
A young friend who hit his head on the corner of his bed. only 22. so sad to have to take him off a respirator.
yardwork
(61,418 posts)That's the killer's story, and he's sticking to it.
According to your links in this thread, no conclusions can be drawn from the tapes.
But since everybody else is bring extra opinion into this thread not related to the OP.
Thought I would too.
We can make a massive thread and give it a nice tree structure.
I'm ready with my links...
pacalo
(24,721 posts)with a self-appointed vigilante who tracked down Trayvon because he didn't like the way Trayvon was walking, or the way he was dressed, or the fact that he didn't recognize the person who was "acting funny" according to him (a proven liar)?
Or do you have something against liberal movie stars & found the opportunity to express your contempt? Otherwise, the comparison isn't relative to this case. Neither is your other comparison: "mall cops" chasing shoplifters.
The fact remains that if this ridiculous self-appointed guardian of the neighborhood had gotten into his car & driven home, Trayvon Martin would have been allowed to go home after a couple of questions by the police, & poor lil' ol' Z-boy wouldn't have gotten the "brain hemorrhage" he claims to have gotten.
grok
(550 posts)One a wannabe "gangsta", by his own words. With all the recklessness and stupidity of youth,the need not to be "DISRESPECTED" and to prove his machismo to others or at least himself.
The other a wannabe "cop". who may not have been doing anything illegal following somebody suspicious, but should have heeded the warning(NOT command). Should have avoided the situation he was not prepared emotionally and intelligently to handle. Do i think having a concealed weapon gave him an extra jolt of bravado? not a clue. My *guess* is he forgot he even had it.
you put two wannabe's together at the wrong time and this is what you get.
If i have contempt, it will be for more than one person. but I don't.
pacalo
(24,721 posts)And, btw, "gangsta" is a widely-used term used by young people today. As I understand it, "He's going gangsta on me" is the way he used the term on the recorded cell phone message. That doesn't make him a "wannabe gangsta".
Indeed, Z wasn't "commanded" to get into his car & leave. That he didn't take the advice provides a very good point for the prosecution, though: Z was looking for a confrontation. He was good to go; he was armed & had a stand-your-ground law to back him up if needed.
grok
(550 posts)and so shouldn't zimmerman's life before. all the evidence should be reduced to just those few minutes before and after and including..
For once we agree on something.
As far as us folk indulging ourselves and playing judge and jury with all the facts and opinion at hand, that's fine for me too. We don't have to decide anything.
And you are entitled proclaim you know EXACTLY what was on zimmerman's mind. Afterall his state of mind is central to much of the case. Intent. In many ways more important than the facts.
I also have an opinion of what was on Martin's mind. and it's not a pleasant one. But it is just an opinion.
And am willing to admit. I just don't know for sure what either was thinking at the time.
Admitting ones ignorance is the beginning of wisdom --Socrates
pacalo
(24,721 posts)The jury deserves to know who Zimmerman is because if not for his thought process & actions that evening, there would be no case. The prosecution plans to point out that Z wanted to be a cop but was rejected & that he was a member of a martial arts gym.
His credibility, also, is important to the case because he is the only one left who can explain exactly what happened. He misled the court in regard to his finances & his wife was charged with perjury for backing him up under oath. The prosecution will also point out the inconsistencies in his police statement; while claiming to the police that he had been "afraid" of Trayvon, why did Z get out of his car?
grok
(550 posts)we should ALSO question whether martin was even capable of even
hurting Z or had the predilection for doing so.
if martin had NEVER had any connection to fighting, theft, guns.violence, never lied to police or school administrators. Had never been sent to his dad's house by his mom to keep him out of trouble for fighting(trayvon's OWN WORDS).. I would say that is VERY good proof that Zimmerman has alot of explaining to do.
The gratuitous what if...
What if Z was black and M was white? what if M was a wannabe skinhead that liked guns,violence and got that suspended for stealing and having drugs on him?
what is Z was a black security guard in a black neighbourhood who just had a rash of burglaries by what appears to have been a gang of skinheads?
what if Z shot when skinhead M started beating him to a pulp but nobody saw it?
Am than willing to give Black Z the benefit of the doubt when he says skinhead M tried to "curb stomp" him to death?
Or am i blindly going to give Black Z life imprisonment because everybody in the neighbourhood skinhead M comes from wants to lynch him, Black Z has not lead a perfect life(who has?) and you refuse to see to the skinhead's record and just blindly assume he was a choirboy?
Guess you think that would be fair.
My point of view is either thisjury should get ALL the evidence, or just ALL the basic facts. It's not fair to limit the evidence for one side and not the other. Particularly when a human being's future is on the line.
pacalo
(24,721 posts)He's the victim who is no longer alive to defend himself or to tell his side of the story.
The only one who can testify as to what happened is the one with a credibility issue. The jury has a right to know his history of lying & of his desire to police others.
I don't care to debate what-ifs, but I will say that if the races of both were reversed, I'd be on the side of the victim who was minding his own business that evening.
All that needs to be presented are the FACTS. ALL the facts are pertinent history.
Martin doesn't need to be defended. he is dead. The LIVING are the only people that need to be DEFENDED.
I remember years ago there used to thousands of schools,buildings, monuments named for long dead ex-confederate heroes, tyrants, murderers, torturers, KKKers. Over time and re-reading of history and FACTS, there was a call for names to be changed to something else like a civil rights leader, somebody who actually did something good..
Oh how some people howled! It's not fair! they can't tell their side of the story or defend themselves! It will hurt them! don't destroy our beloved memory of them!
Hogwash. Names were changed and TRUTH reigned. And the living were better for it.
You can't honor dead people anyways with hiding the truth. If people are imperfect, that's ok. We don't have to have our saints be perfect to honor what they did in life. OR learn from their mistakes.
yardwork
(61,418 posts)In order to believe Zimmerman's story we have to believe that:
1. George Zimmerman, after calling 911 and stating that he was chasing a "suspect," making several bigoted slurs about the person he was following, suddenly changed his mind and started walking back to his vehicle and that
2. The person George Zimmerman had been following - the person Zimmerman said was running away from him and likely to "get away," according to Zimmerman's own recorded words - suddenly turned around and attacked Zimmerman while Zimmerman was trying to get back to his truck.
I don't believe that. I can see why Zimmerman has made up that story, but I think it is not believable.
Instead, it's much more likely that Zimmerman continued doing exactly what he said he was doing, as recorded on the 911 calls. He chased Trayvon until he caught up with him. Zimmerman probably grabbed or jumped on Trayvon and tried to apprehend him himself. Trayvon probably fought back. it looks like he got a couple of good punches in before Zimmerman pulled out the gun and shot Trayvon dead. To call this justifiable self-defense on Zimmerman's part is patently ridiculous.
grok
(550 posts)1. The "bigoted" slur was proven to have been doctored by a NBC technician. It's not in the official docket of evidence. NBC is now being sued by Zimmerman and WILL win..
http://www.cnn.com/2012/12/06/us/florida-zimmerman-nbc-lawsuit
CNN actually did the same thing in a different way but corrected themselves almost immediately. this was actually more egregious. Think somebody got fired even though the recording spread.
2. You might be right. However, Zman could be telling the truth. The lay of the land makes it convenient for both scenarios to be equally plausible.
.
.
wandy
(3,539 posts)recognition software STOP. It don't work!
I guess that was just another Bush lie about analyzing the cave tapes to see if it was Bin Laden.
Stevie Nicks (vocal cord nodules) doesn't create different ones and zeros on digital recording than Judy Collins.
I guess they just sound different.
This is going to tweek the Autotune Evo folk off. They can't key off the ones and zeros of a speech, change pitch and make the speaker sing.
I guess Christine O'Donnell really wasn't a witch.
The infinite entertainment as the made for TV Zimmerman movie goes through various rewrites.
wickerwoman
(5,662 posts)It has about 80% accuracy for speech-to-text with an open dictionary and can get up to 95% accurate where the probable responses can be narrowed down to a smaller set. Many deaf people use speech-to-text speech recognition software (like Dragon) which has been on the market for more than a decade.
What doesn't work is speech identification software in a law enforcement context.
7962
(11,841 posts)And they arent allowed in court too.
wandy
(3,539 posts)Does this not work because of the dictionary required for legal terms.
Or is it because the ones and zeros are not admissible evidence.
Like this......
For person A we get
20 20 20 32 35 30 20 42 ----------and on and on into the night
For person B we get
20 21 31 32 20 36 22 39 ---------------->
I wonder if I may have answered my own question. At this level the voice can be manipulated. As in...
I'm not a witch either.
Now I am curious.
Dragon is a good thing. My first experience with speech-to-text involved a PC AT and the original IBM VCO card.
Fear and loathing in PC Assembler.
Auntie Bush
(17,528 posts)poor speller who has to write business letters.
wandy
(3,539 posts)I am worse than a poor speller. In the end it may come down to the spell checker.
I also have the joy of business letters.
Although a touch pricey Microsoft Office keeps me compatible with my customers and what is more if I'm careful, keeps me from spelling like a Teabagger.
Did a little looking around. Not sure if this will do the trick but for $12.50 this may be worth looking into.
http://www.amazon.com/Dragon-Naturally-Speaking-Basics-Version/dp/B004MKBXGY/ref=sr_1_13?ie=UTF8&qid=1370744920&sr=8-13&keywords=naturally+speaking+dragon
At least, something to look at.
Auntie Bush
(17,528 posts)I thought it was about 70 some odd dollars. I was thinking Xmas but at price...Father's Day!
pacalo
(24,721 posts)(...)
Owen said that in general, it was much easier to make a positive elimination than an identification. On cross-examination, however, he said that the amount of screaming was enough to definitively rule out George Zimmerman.
(...)
Experts have come to mixed conclusions about the screaming in the background of the 911 call. One state expert, who could prove crucial to prosecutors if the judge allows the jury to hear his testimony, said he heard Martin screaming and saying "I'm begging you" in the background of the call.
http://www.cbsnews.com/8301-504083_162-57588238-504083/george-zimmerman-update-audio-expert-testifies-accused-killer-zimmerman-is-likely-not-the-person-screaming-in-911-call/