Question about Dr. Donald Thomas’s Dictabelt Offset Hypothesis

[Joe Elliott]

Joe and Otto, if you want to educate yourselves on the basics of the acoustical evidence, I suggest you watch the following video made by Dr. Thomas in 2014. He covers a lot of the evidence that the dictabelt contains gunfire--not all of it, but a lot of it. He also addresses the crosstalk issue and the Sonalysts study. You'll want to watch the Q&A segment as well, which includes questions from Dr. Mantik and from one of the HSCA staffers who worked with the HSCA acoustical experts. The video is only 40 minutes long and includes lots of graphics.

https://aarclibrary.org/dr-donald-b-thomas-jfk-acoustical-evidence-challenge-and-corroboration/

A few observations:

1.   The Question and Answer period. Every single one of those people were fans of Dr. Thomas. Nobody asked any tough questions, which I would like asked.

2.   My favorite questioner?

The guy at 36:30 informed them that he saw proof that Gerald Ford moved up the bullet in the back of JFK nine inches. Nine inches! Yes, it had to be moved up 9 inches because it turned out that the actual shot came from a blimp firing from the front, but firing down at an angle of 50 degrees (arctan(7/6) = 50 degrees), resulting in a back wound that was 7 inches lower than the throat wound. But, by moving the wound up 9 inches, instead of the back wound being 7 inches below the throat wound, it was now two inches higher, allowing them to say the bullet came from the back coming down at an angle of 18 degrees (arctan(2/6) = 18 degrees) from the sixth floor window.

3.   But what stood out the most was him playing a snippet of the recording from the motorcycle with the stuck microphone. And there was a motorcycle with a stuck microphone. At 7:40, Dr. Thomas plays the recording starting at 12:32 CST on November 1963. He plays it for about 8 seconds. You can hear loud sirens, clearly nearby, during the 8 seconds. This clearly gives the impression that the motorcycle with the stuck microphone was travelling with the Presidential limousine, with sirens blaring, on the way the Parkland hospital. Indeed, even the Police Dispatcher thought so and tried to get someone to find that officer so the key could be unstuck and free up Channel 1 for emergency communication. However, the Police Dispatcher forgot that in addition to having motorcycles accompanying the Presidential limousine, he also had motorcycles waiting at the Trade Mart, where the President was scheduled to give a speech. And that same freeway passes by the Trade Mart Center. Well, if you play the entire 5-minute segment, during the time the limousine was driven at high speed to the hospital, you don’t hear continuous sirens for 5 minutes. Instead, things are quiet, then one can hear the sound of approaching sirens. The sirens are quite loud for a few seconds, and then the sound of the sirens gradually fade away. The you hear sirens approaching again, get loud and fade away. And then a third time the sirens get loud and fade away. This is the sort of noise one would hear from a motorcycle waiting at the Trade Mart Center, not with a motorcycle travelling with limousine to the hospital.

Now, Dr. Thomas isn’t exactly lying here. He did play the authentic recording. But he was being quite deceitful. He only played 8 seconds of sirens. It was only the section where the sirens were loud. Had he played the whole thing, and it would only have taken 5 minutes, his case would have collapsed.

So, yes, I did learn a thing or two about the good Dr. Thomas.

[Michael T. Griffith]

Quote from: Otto Beck on September 16, 2020, 09:48:35 AM
Joe, it would be easier to follow your argument by using the actual material published by Dr. Thomas and object to what you believe is wrong. One source of "Hear No Evil" is here: http://www.whokilledjfk.net/hear_no_evil.htm

If you go to section FILMED EVIDENCE OF THE MOTORCYCLE you have a table of shots and Z-frames (Table 1). It says that "Tape Times from BBN Report Table 2.", which I haven't checked, but the times you're asking for should be there.

Edit: unfortunately the figures don't display in the url I listed above.

Thank you Otto. This information is most helpful. I’ll start another thread on it in a day or two. At a glance, I can see why Mr. Griffith was not giving us this information directly, even though, . . .

What a bunch of lying nonsense. I have provided links to Dr. Thomas's articles in several of my replies. I've also provided citations from his book in some of my replies. I've also provided a link to one of Dr. Thomas's videos on the acoustical evidence. Just a few replies ago, I provided a link to one of Dr. Thomas's discussions on correlating the dictabelt and the Zapruder film. I also cited the pages in his book where he discusses this issue.

First you whine and complain because I have provided long quotes from Dr. Thomas's articles in some of my replies, but then you turn around and claim that I have not been "giving us this information directly."

the initial impression, is that it matches up with the Zapruder film. But I will show that this is bogus.

Yeah, uh-huh. You will do no such thing. You don't even know the basics about the acoustical evidence. You have committed one embarrassing gaffe after another. Just a few replies ago, you made the jaw-dropping claim that conspiracy theorists "don't like" to talk about whether the dictabelt shots correlate with the Zapruder film shots, which proves you have not read the HSCA materials and have not read Dr. Thomas's research. You've devoted several replies to utterly batty claims about offsets, proving you have not even read the NRC panel's report, much less Dr. Thomas's research on the subject.

Question for Joffrey van de Wiel

Has Mr. Griffith answered your questions about the number of the “shots” on the Dictabelt recording?
And the timing of these “shots”?
And the source of each “shot” (TSBD, Grassy Knoll, etc.)?
And which Zapruder frame each “shot” corresponds to?

Have you found that there is the excellent correlation between the answers that Mr. Griffith has given you and the Zapruder film as he claims we can find?

Or have you found that Mr. Griffith has been evasive, as I predicted.

And if you haven’t found Mr. Griffith to be evasive, how many “gunshots” are to be found on the Dictabelt recording?

What a bald-faced liar you are. Well, you're either a bald-faced liar or you have not read most of my replies. I've discussed and provided links on every single one of the issues you mention. Are you just hoping that people who read this thread won't go back and check my previous replies or something? Because if they do, they're gonna wonder how you could make such demonstrably false statements.

Otto Beck
If the Decker/Fisher pair result from cross talk (coming from Channel-2) and Channel-1 records uninterrupted in real time there is no way the Decker/Fisher pair on Channel-2 can be spaced further apart in time that on Channel-1.

If synchronized using the Fischer broadcast the Decker arrives too late on CH-2, if synchronized using the Decker broadcast the Fischer broadcast on CH-1 evidently can't be simulcast.

Since CH-2 is voice activated, simulcasts must be equally or closer spaced on CH-2, something is not right here.

LOL! This is downright funny. Now, I know you copied this from some pro-WC website, and you clearly do not understand what you said. It's obvious you still have not read Dr. Thomas's research, because Dr. Thomas addresses these and other issues regarding the timing of the Decker, Bellah, Curry, and Fisher crosstalk episodes in great detail.

The Decker crosstalk is the most problematic and out-of-sync of all the crosstalk episodes. But you guys pick it as your time anchor because that's the only way you can claim that the gunshots on the dictabelt occur after the assassination. Let me repeat what I've written elsewhere:

* According to the DPD dispatcher’s “12:30” time notation on Channel 2, the gunshots were recorded during the assassination. Yes, the dispatcher on each channel periodically gave time notations, and on the dictabelt the Channel 2 dispatcher voices the time notation “12:30” at virtually the same time the gunshots occur on the dictabelt on Channel 1.

* The first gunshot on the dictabelt occurs just 2 seconds after the Fisher “I’ll check it” crosstalk, and the Fisher transmission occurs just before the dispatcher notes “12:30” on Channel 2.

* The first gunshot on the dictabelt occurs just after Curry’s “triple underpass” transmission. This transmission comes right after Fisher’s “I’ll check it” transmission and just before the dispatcher’s “12:30” time notation. Curry’s “triple underpass” transmission was made to note that the motorcade was on Elm Street and that his car was approaching the triple underpass (his car was ahead of the presidential limo).

* The final gunshot on the dictabelt, which comes 8.3 seconds after the first one, occurs about 10 seconds before Curry’s “to the hospital” transmission, and we know Curry’s “to the hospital” transmission was made 18 seconds after his “triple underpass” transmission.

* Thus, it is very clear that the gunshots on the dictabelt were recorded during the 18 seconds between Fisher’s “I’ll check it” transmission and Curry’s “to the hospital” transmission. Curry yelled “go to the hospital” after he saw that JFK had been wounded, after Curry’s car slowed down to let the limo catch up with it and pass it, and we know when this happened because the event is captured on the Zapruder film.

[Joffrey van de Wiel]

Why no, I don’t mind being called ignorant from someone who has been as evasive as you.


Question for Joffrey van de Wiel

Has Mr. Griffith answered your questions about the number of the “shots” on the Dictabelt recording?
And the timing of these “shots”?
And the source of each “shot” (TSBD, Grassy Knoll, etc.)?
And which Zapruder frame each “shot” corresponds to?

Have you found that there is the excellent correlation between the answers that Mr. Griffith has given you and the Zapruder film as he claims we can find?

Or have you found that Mr. Griffith has been evasive, as I predicted.

And if you haven’t found Mr. Griffith to be evasive, how many “gunshots” are to be found on the Dictabelt recording?


And Joffrey, if you have found Mr. Griffith to be evasive, don’t waste your time and money on Dr. Thomas’s “Hear No Evil”. You will find that Dr. Thomas does not answer these questions either, and is just as evasive as Mr. Griffith.

Sir,

I just noticed your questions for me because my internet connection broke down. I apologize for not responding sooner.

Let me first state then, that I think Mr. Griffith is a very astute researcher and author. I don't think he is being evasive, or is just copying and pasting as a quick way to respond to questions or prove his point. The problem for me is trying to comprehend his (and yours, for that matter) reasoning as I lack sufficient knowledge of physics in general and acoustics in particular. On top of that, I don't understand how a dictabelt recording device works. It is apparently capable of recording human voices, church bells and sirenes, but unable to record the loud bang associated with a gun shot. Then there appear on the recording these high-pitched tones which are unexplained.

I have viewed a presentation of Dr. Thomas on YouTube. Much of it went over my head but as I understand it the following is true:

1) On the day of the assassination, the Dallas Police radio channel 1 was reserved for regular police communications;
2) On the day of the assassination, the Dallas Police radio channel 2 was reserved for the Presidential motorcade;
3) Channel 2 radio traffic was recorded on a Dicta-belt;
4) At a certain time, the microphone of one of the escorting motorcycle officers in the Presidential parade got stuck on the 'transmit' position.

The points of contention are:

1) There was no microphone stuck on the 'transmit' position in the motorcade, and if there was, it was nowhere near Dealey Plaza at 12:30 p.m.;
2) The open microphone did not record any gunshots;
3) The impulses shown on the audiograph are not gunshots but random impulses created by ambient noise;
4) The dictabelt recording can not be matched to the Zapruder film because it has been altered;
5) The four to six shots recorded by the dictabelt contradict the Warren Commission's findings therefore it can not possibly be true;
6) Some gunshot impulses on the recording can not be matched to any test shots, therefore the acoustic evidence is invalid.

I'm missing a few perhaps. I joined this Forum in order to learn something. It is dedicated to a debate about the JFK assassination. A debate is worthless when one is not willing or able to consider the points of view put forward by its participants. I am weighing the evidence put forward by both sides of the equation and hope to come to some sort of conclusion in the near future. 

Meanwhile I remain respectfully yours,

Joffrey

(edited for grammar and translation errors.)

[Michael T. Griffith]

For the sake of those who might be new to the HSCA’s acoustical evidence of four gunshots, or for those who have read one or two articles on the subject and who want to learn more, below are some helpful excerpts from the section on the acoustical evidence in the HSCA’s final report. This report was aimed at the average reader, so the authors made every effort to explain the acoustical evidence in plain English as much as possible. If you are trying to make heads or tails of this thread, these excerpts should be helpful.

To the human ear, the tapes and Dictabelts contain no discernible sounds of gunfire. The dispatcher's voice notations of the time of day indicate that channel 2 apparently was not in use during the period when the shots were fired. Channel 1 transmissions, however, were inadvertently being recorded from a motorcycle or other police vehicle whose radio transmission switch was stuck in the "on" position.(10) BBN was asked to examine the channel 1 Dictabelts and the tape that was made of them to see if it could determine: (1) if they were, in fact, recorded transmissions from a motorcycle with a microphone stuck in the "on" position in Dealey Plaza; (2) if the sounds of shots had been, in fact, recorded; (3) the number of shots; (4) the time interval between the shots; (5) the location of the weapon or weapons used to fire the shots; and (6) the type of weapon or weapons used.

BBN converted the sounds on the tape into digitized waveforms and produced a visual representation of the waveforms.(11) By employing sophisticated electronic filters, BBN filtered out "repetitive noise," such as repeated firings of the pistons of the motorcycle engine.(12) It then examined the tape for "sequences of impulses" that might be significant. (A "sequence of impulses" might be caused by a loud noise--such as gunfire--followed by the echoes from that loud noise.) Six sequences of impulses that could have been caused by a noise such as gunfire were initially identified as having been transmitted over channel 1.(13) Thus, they warranted further analysis.

These six sequences of impulses, or impulse patterns, were subjected to preliminary screening tests to determine if any could be conclusively determined not to have been caused by gunfire during the assassination. The screening tests were designed to answer the following questions:(14)

-- Do the impulse patterns, in fact, occur during the period of the assassination?
-- Are the impulse patterns unique to the period of the assassination?
-- Does the span of time of the impulse patterns approximate the duration of the assassination as indicated by a preliminary analysis of the Zapruder film? (Are there at least 5.6 seconds between the first and last impulse? 4)
-- Does the shape of the impulse patterns resemble the shape of impulse patterns produced when the sound of gunfire is recorded through a radio transmission system comparable to the one used the Dallas police dispatch network?
-- Are the amplitudes of the impulse patterns similar to those produced when the sound of gunfire is recorded through a transmission system comparable to the one used for the Dallas police dispatch network?

All six impulse patterns passed the preliminary screening tests.(15)

BBN next recommended that the committee conduct an acoustical reconstruction of the assassination in Dealey Plaza to determine if any of the six impulse patterns on the dispatch tape were caused by shots and, if so, if the shots were fired from the Texas School Book Depository or the grassy knoll.(16) The reconstruction would entail firing from two locations in Dealey Plaza--the depository and the knoll--at particular target locations and recording the sounds through numerous microphones. The purpose was to determine if the sequences of impulses recorded during the reconstruction would match any of those on the dispatch tape. If so, it would be possible to determine if the impulse patterns on the dispatch tape were caused by shots fired during the assassination from shooter locations in the depository and on the knoll.(17). . . .

. . . it was deemed judicious to seek an independent review of Barger's analysis before proceeding with the acoustical reconstruction. So, in July 1978, the committee contacted the Acoustical Society of America to solicit recommendations for persons qualified to review the BBN analysis and the proposed Dallas reconstruction. The society recommended a number of individuals, and the committee selected Prof. Mark Weiss of Queens College of the City University of New York and his research associate, Ernest Aschkenasy. Professor Weiss had worked on numerous acoustical projects. He had served, for example, on the panel of technical experts appointed by Judge John J. Sirica to examine the White House tape recordings in conjunction with the Watergate grand jury investigation. Aschkenasy had specialized in developing computer programs for analyzing large volumes of acoustical data. . . .

A recording was made of the sounds received at each microphone location during each test shot, making a total of 432 recordings of impulse sequences (36 microphone locations times 12 shots), or "acoustical fingerprints," for various target-shooter-microphone combinations. Each recorded acoustical fingerprint was then compared with each of the six impulse patterns on the channel 1 dispatch tape to see if and how well the significant points in each impulse pattern matched up. The process required a total of 2,592 comparisons (432 recordings of impulse sequences times six impulse patterns), an extensive effort that was not completed until 4 days before Barger was to testify at a committee public hearing on September 11, 1978.(26)

The time of the arrival of the impulses, or echoes, in each sequence of impulses was the characteristic being compared, not the shape, amplitude or any other characteristic of the impulses or sequence.(27) If a point (representing time of arrival of an echo) in a sequence of the 1963 dispatch tape could be correlated within plus or minus 6/1,000 of a second to a point in a sequence of the reconstruction, it was considered a match.(28)

A plus or minus 6/1,000 of a second "window" was chosen, because the exact location of the motorcycle was not known. Since the microphones were placed 18 feet apart in the 1978 reconstruction, no microphone was expected to be in the exact location of the motorcycle microphone during the assassination in 1963. Since the location was not apt to be exactly the same, and the time of arrival of the echo is unique at each spot, the +-6/1,000 of a second "window" would allow for the contingency that the motorcycle was near, but not exactly at, one of the microphone locations selected for the reconstruction.(29)

Those sequences of impulses that had a sufficiently high number of points that matched (a "score" or correlation coefficient of .6 or higher) were considered significant.(30) The "score" or correlation coefficient was set at this level to insure finding all sequences that might represent a true indication that the 1963 dispatch tape contained gunfire. Setting it at this level, however, also allowed a sequence of impulses on the dispatch tape that might have been caused by random noise or other factors to be considered a match and therefore significant.(31) Such a match, since it did not in fact represent a true indication of gunfire on the 1963 dispatch tape, would be considered an "invalid match."(32)

Of the 2,592 comparisons between the six sequences of impulses on the 1963 police dispatch tape and the sequences obtained during the acoustical reconstruction in August 1978, 15 had a sufficient number of matching points (a correlation coefficient of .6 or higher) to be considered significant.(33) The first and sixth sequence of impulses on the dispatch tape had no matches with a correlation coefficient over .5. The second sequence of impulses on the dispatch tape had four significant matches, the third sequence had five, the fourth sequence had three, and the fifth sequence had three.(34) Accordingly, impulses one and six on the dispatch tape did not pass the most rigorous acoustical test and were deemed not to have been caused by gunfire from the Texas School Book Depository or grassy knoll.(35) Additional analysis of the remaining four impulse sequences was still necessary before any of them could be considered as probably representing gunfire from the Texas School Book Depository or the grassy knoll.

The locations of the microphones that recorded the matches in the 1978 reconstruction were plotted on a graph that depicted time and distance. It was observed that the location of the microphones at which matches were recorded tended to cluster around a line on the graph that was, in fact, consistent with the approximate speed of the motorcade (11 mph), as estimated from the Zapruder film.(36) For example, of the 36 microphones placed along the motorcade route, the one that recorded the sequence of impulses that matched the third impulse on the 1963 dispatch tape was farther along the route than the one that recorded the impulses that matched the second impulse on the dispatch tape. The location of the microphones was such, it was further observed, that a motorcycle traveling at approximately 11 miles per hour would cover the distance between two microphones in the elapsed time between impulses on the dispatch tape. This relationship between the location of the microphones and the time between impulses was consistent for the four impulses on the dispatch tape, a very strong indication, the committee found, that the impulses on the 1963 dispatch tape were picked up by a transmitter on a motorcycle or other vehicle as it proceeded along the motorcade route. Applying a statistical formula, Barger estimated that since the microphones clustered around a line representing the speed of the motorcade, there was a 99 percent probability that the Dallas police dispatch tape did, in fact, contain impulses transmitted by a microphone in the motorcade in Dealey Plaza during the assassination.(37). . . .

In mid-September 1978, the committee asked Weiss and Aschkenasy, the acoustical analysts who had reviewed Barger's work, if they could go beyond what Barger had done to determine with greater certainty if there had been a shot from the grassy knoll. Weiss and Aschkenasy conceived an analytical extension of Barger's work that might enable them to refine the probability estimate.(45) They studied Dealey Plaza to determine which structures were most got to have caused the echoes received by the microphone in the 1978 acoustical reconstruction that had recorded the match to the shot from the grassy knoll. They verified and refined their identifications of echo-generating structures by examining the results of the reconstruction. And like BBN, since they were analyzing the arrival time of echoes, they made allowances for the temperature differential, because air temperature affects the speed of sound.(46) Barger then reviewed and verified the identification of echo-generating sources by Weiss and Aschkenasy.(47)

Once they had identified the echo-generating sources for a shot from the vicinity of the grassy knoll and a microphone located near the point indicated by Barger's tests, it was possible for Weiss and Aschkenasy to predict precisely what impulse sequences (sound fingerprints) would have been created by various specific shooter and microphone locations in 1963.(48) (The major structures in Dealey Plaza in 1978 were located as they had been in 1963.) Weiss and Aschkenasy determined the time of sound travel for a series of sound triangles whose three points were shooter location, microphone location and echo-generating structure location. While the location of the structures would remain constant, the different combinations of shooter and microphone locations would each produce a unique sound travel pattern, or sound fingerprint.(49) Using this procedure, Weiss and Aschkenasy could compare acoustical fingerprints for numerous precise points in the grassy knoll area with the segment identified by Barger on the dispatch tape as possibly reflecting a shot fired from the knoll.(50) 10

Because Weiss and Aschkenasy could analytically construct what the impulse sequences would be at numerous specific shooter and microphone locations, they decided to look for a match to the 1963 police dispatch tape that correlated to within ±1/1.000 of a second, as opposed to +-6/1.000) of a second, as Barger had done.(51) By looking for a match with such precision, they considerably reduced the possibility that any match they found could have been caused by random or other noise,(52) thus substantially reducing the percentage probability of an invalid match. . . .

Approximately 10 feet from the point on the grassy knoll that was picked as the shooter location in the 1978 reconstruction and four feet from a microphone location which, Barger found, recorded a shot that matched the dispatch tape within +-6/1,000 of a second, Weiss and Aschkenasy found a combination of shooter and microphone locations they needed to solve the problem. It represented the initial position of a microphone that would have received a series of impulses matching those on the dispatch tape to within +-1/1.000 of a second. The microphone would have been mounted on a vehicle that was moving along the motorcade route at 11 miles per hour.

Weiss and Aschkenasy also considered the distortion that a windshield might cause to the sound impulses received by a motorcycle microphone. They reasoned that the noise from the initial muzzle blast of a shot would be somewhat muted on the tape if it traveled through the windshield to the microphone. Test firings conducted under the auspices of the New York City Police Department confirmed this hypothesis. Further, an examination of the dispatch tape reflected similar distortions on shots one, two, and three, when the indicated positions of the motorcycle would have placed the windshield between the shooter and the microphone.11 On shot four, Weiss and Aschkenasy found no such distortion.(55) The analysts' ability to predict the effect of the windshield on the impulses found on the dispatch tape, and having their predictions confirmed by the tape, indicated further that the microphone was mounted on a motorcycle in Dealey Plaza and that it had transmitted the sounds of the shots fired during the assassination.

Since Weiss and Aschkenasy were able to obtain a match to within +-1/1,000 of a second, the probability that such a match could occur by random chance was slight. Specifically, they mathematically computed that, with a certainty factor of 95 percent or better, there was a shot fired at the Presidential limousine from the grassy knoll.(56)

Barger independently reviewed the analysis performed by Weiss and Aschkenasy and concluded that their analytical procedures were correct.(57) Barger and the staff at BBN also confirmed that there was a 95 percent chance that at the time of the assassination a noise as loud as a rifle shot was produced at the grassy knoll. When questioned about what could cause such a noise if it were not a shot, Barger noted it had to be something capable of causing a very loud noise--greater than a single firecracker.(58) Further, given the echo patterns obtained, the noise had to have originated at the very spot behind the picket fence on the grassy knoll that had been identified,(59) indicating that it could not have been a backfire from a motorcycle in the motorcade.(60)

In addition, Barger emphasized, the first part of the sequence of impulses identified as a shot from the grassy knoll was marked by an N-wave, a characteristic impulse caused by a supersonic bullet.(61) The N-wave, also referred to as a supersonic shock wave, travels faster than the noise of the muzzle blast of a gun and therefore arrives at a listening device such as a microphone ahead of the noise of a muzzle blast. The presence of the N-wave was, therefore, a significant additional indication that the third impulse on the police dispatch tape represented gunfire, and, in particular, a supersonic bullet.(62) The weapon may well have been a rifle, since most pistols except for some such as a .44 magnum--fire subsonic bullets. The N-wave was further substantiation for a finding that the third impulse represented a shot fired in the direction of the President. Had the gun been discharged when aimed straight up or down, or away from the motorcade, no N-wave would have appeared.(63) Of the impulse patterns on the dispatch tape that indicated shots from the book depository, those that would be expected to contain an N-wave, given the location of the vehicle's microphone, did so, further corroborating the conclusion that these impulses did represent supersonic bullets.(64) (HSCA report, pp. 68-75)

[Gerry Down]

2) The open microphone did not record any gunshots;
3) The impulses shown on the audiograph are not gunshots but random impulses created by ambient noise;

This is what gets me. Shouldn't a person be able to hear shots on the dictabelt recording?

[Michael T. Griffith]

The points of contention are:

1) There was no microphone stuck on the 'transmit' position in the motorcade, and if there was, it was nowhere near Dealey Plaza at 12:30 p.m.;
2) The open microphone did not record any gunshots;
3) The impulses shown on the audiograph are not gunshots but random impulses created by ambient noise;
4) The dictabelt recording can not be matched to the Zapruder film because it has been altered;
5) The four to six shots recorded by the dictabelt contradict the Warren Commission's findings therefore it can not possibly be true;
6) Some gunshot impulses on the recording can not be matched to any test shots, therefore the acoustic evidence is invalid.

Let me answer these by their number.

1. We know this is wrong because the Channel 2 dispatcher told all the patrolmen that a patrolman "up on Stemmons" had his mike stuck on, and he asked them to try to find him and get him to shut off his mike. The "up on Stemmons" comment is evidence that McClain was the one with the stuck mike.

2. This is a summary claim that I think is totally refuted by the evidence. For example, there are N-waves from supersonic rifle fire on the dictabelt on the shots that were recorded when the microphone was in a position to record N-waves, and the grassy knoll shot's N-wave comes 24 milliseconds before its trailing muzzle blast, just as it should. N-waves from rifle fire typically come 10-30 milliseconds before the muzzle blast behind them. 

3. This is another summary claim that I think is also totally refuted by the evidence. The correlations between the dictabelt gunfire impulse patterns and the test-firing impulse patterns are powerful, compelling evidence that the dictabelt contains recorded assassination gunfire.

4. Yet, there are definite correlations between the dictabelt gunshots and gunfire reactions in the Zapruder film, somewhat to my surprise. It is entirely possible that the Zapruder film was not altered enough to prevent it from correlating with the dictabelt. Much of the alteration involved adding, removing, and doctoring images on the film, which would not affect correlation with the dictabelt. Also, since the dictabelt might not have recorded one of the shots fired at JFK, because of how the shot was fired and because of the DPD dispatch system's AGC circuitry, it just might be that this unrecorded shot is part of the reason that the dictabelt does correlate rather well with the Zapruder film.

5. Yes, believe it or not, some people make that argument.

Speaking of the WC, we now know that the commission had an analysis done on a KBOX radio station recording that was made in Dealey Plaza during the assassination. The analysis was done by acoustical expert Larry Kersta at the Bell Telephone Lab in New Jersey. Kersta only had the equipment to do a spectrographic analysis of the tape, but he found that it contained six "non-voiced" noises! Moreover, the KBOX "non-voiced" noises follow the same sequence and pattern as do the six dictabelt impulses that passed the first BBN screening for gunfire: the first one is different from the others, followed by three impulses close together, followed by a slight pause, followed by two more impulses similar to the previous three. My, my, my, what an amazing coincidence.

6. I don't know who said that, but they must not have read any of the HSCA materials. Only five of the impulse patterns met all of the BBN screening criteria for gunfire, and all five of those impulse patterns match shots from the Dealey Plaza test firing. I might add that no other impulse pattern anywhere on the 5.5-minute dictabelt segment met all the BBN criteria for gunfire.

[John Iacoletti]

Speaking of the WC, we now know that the commission had an analysis done on a KBOX radio station recording that was made in Dealey Plaza during the assassination.

Which, by the way, is one of the many original pieces of evidence that "can't be located".  The common recording we've all heard ("it appears something has happened in the motorcade route") is a re-creation.

[Joe Elliott]

Joe, it would be easier to follow your argument by using the actual material published by Dr. Thomas and object to what you believe is wrong. One source of "Hear No Evil" is here: http://www.whokilledjfk.net/hear_no_evil.htm

If you go to section FILMED EVIDENCE OF THE MOTORCYCLE you have a table of shots and Z-frames (Table 1). It says that "Tape Times from BBN Report Table 2.", which I haven't checked, but the times you're asking for should be there.

Edit: unfortunately the figures don't display in the url I listed above.

Thank you Otto. This information is most helpful. I’ll start another thread on it in a day or two. At a glance, I can see why Mr. Griffith was not giving us this information directly, even though, the initial impression, is that it matches up with the Zapruder film. But I will show that this is bogus.

What a bunch of lying nonsense. I have provided links to Dr. Thomas's articles in several of my replies. I've also provided citations from his book in some of my replies. I've also provided a link to one of Dr. Thomas's videos on the acoustical evidence. Just a few replies ago, I provided a link to one of Dr. Thomas's discussions on correlating the dictabelt and the Zapruder film. I also cited the pages in his book where he discusses this issue.

No. You provided a bunch of links without saying which link has the information I requested. Otto, in contrast, gave me just one link, that was just a few pages long, that provided the information.

You provided no link to (until after Otto did):

http://www.whokilledjfk.net/hear_no_evil.htm

Or any other similar website where the information is right there.


You don’t have to find such a website. It would have been as simple just type out:

The BBN found shots at z175 (TSBD), z204 (TSBD), z312 (Knoll) and z326 (TSBD). And Dr. Thomas found a fifth at z224 (TSBD).


I think that you wanted to keep it a secret, at least from the casual views, of a first shot at z175, which really make it difficult for Officer McLain to be there for the first shot.