Acoustic Evidence

[Steve Barber]

 MTG can't get it through his head that no matter what Thomas said in any of his writings or lectures, the radio transmission Thomas claims is "I'll check it" crosstalk on channel 1 is both bogus and nothing but a lie by Thomas.

 The fact that heterodyne tones accompany (Surround, if you will)  the speech by someone opening their microphone on channel 1 and speaking into the microphone is proof solid that it's not crosstalk.  The heterodyne tones prove this.  It is in no way, shape or form "crosstalk". End of story.

[Michael T. Griffith]

MTG can't get it through his head that no matter what Thomas said in any of his writings or lectures, the radio transmission Thomas claims is "I'll check it" crosstalk on channel 1 is both bogus and nothing but a lie by Thomas.

The fact that heterodyne tones accompany (Surround, if you will)  the speech by someone opening their microphone on channel 1 and speaking into the microphone is proof solid that it's not crosstalk.  The heterodyne tones prove this.  It is in no way, shape or form "crosstalk". End of story.

LOL! So in answer to my reply, you merely repeated your response! Ok, then let me repeat what I said in reply to your claims:

You have no clue what you are talking about. I wonder if you even read my reply. I'm certain you haven't read the 2015-2018 research done by BBN acoustical scientists. I doubt you've even read a small portion of Dr. Thomas's hundreds of pages of research on the acoustical evidence.

Did you miss the fact that even Bowles admitted that the Fisher "I'll check" transmission is crosstalk? Again, did you even read my reply or did you just glance at it before you rubber-stamped Corbett's inane reply?

Did you miss the fact that Dr. Mullen's PCC test proved that the Fisher "I'll check" transmission is actual crosstalk and that the Decker "hold everything" transmission is nothing but an overdub that was not even recorded at the same speed as the acknowledged crosstalk transmissions?

As for your spurious argument that the Fisher transmission can't be crosstalk because it is accompanied by heterodyne tones, I take it you're unaware that heterodyne tones also occur near and during the Decker transmission. So, according to you, the Decker transmission can't be crosstalk. You would have known better than to repeat the heterodyne argument if you had read Dr. Thomas's research or Dr. Thompson's research.

BTW, Linsker and his colleagues tried to conceal the fact that even their own incompetently done PCC test disqualified the Decker transmission as crosstalk if they accepted the heterodyne argument (Thompson, Last Second in Dallas, p. 512).

This whole erroneous heterodyne argument started with the NRC/NAS panel because they didn't understand the relationship of the transmitters and didn't understand how broadcasts can be superimposed from one channel onto another. They wrongly assumed that the Channel 2 broadcast had been picked up over the motorcycle's transmitter, i.e., its open microphone, but the broadcast was actually picked up by another transmitter, most likely a police unit parked at the Trade Mart where police officers had gathered for JFK's expected arrival.

The NRC/NAS panel also wrongly assumed that the differences in the energy in the Channel 1 heterodynes and the Channel 2 heterodynes proved that the Decker transmission must have been recorded in real time, because they didn't understand that a broadcast from one channel could have been superimposed on another channel in real time. If the panel members had bothered to consult with the BBN and Queens College acoustical scientists, the scientists could have educated them on this issue.

I doubt you have any interest in doing so, but if you want to read a scientific analysis that includes a discussion of the heterodyne tones heard on the dictabelt, see Appendix B in Thompson's book. The appendix was written by BBN acoustical scientist Dr. Richard Mullen and is titled "Signal Processing Results for Both DPD Audio Files."

You should also read BBN acoustical scientist Dr. James Barger's detailed discussion on the criteria to establish crosstalk in the dictabelt. It's titled "Quantitative Analysis of Crosstalk Found in Audio Recorded During the JFK Assassination" and is Appendix A in Thompson's book.

[Michael T. Griffith]

As noted earlier, Dale Myers claims that the report produced by the NRC/NAS panel (also known as the CBA or the Ramsey Panel) is a “devastating critique” of the HSCA’s acoustical evidence. Not even close. Let’s take another look at this supposedly “devastating critique”:

-- As part of their recalculation of the probability that the dictabelt’s 144.9 impulse pattern was a shot from the grassy knoll, the NRC/NAS panel arbitrarily and wrongly assumed there were two degrees of freedom associated with the shooting position, but in fact there was only one degree of freedom, as MIT mathematician Dr. David Scheim pointed out:

For example, the critical Weiss-Aschkenasy conclusion of a 95-percent
probability of a grassy knoll shot was treated only in a sketchy three-page
appendix [in the NRC/NAS panel's report] that made one outright error -- there was only
one degree, not two, of freedom associated with the position of the shooter along
the grassy knoll fence. (Scheim, The Mafia Killed President Kennedy, 1992, p. 408 n 120)

-- In another facet of their effort to reduce the probability of the grassy knoll shot, the NRC/NAS panel used the curious, invalid approach of subtracting degrees of freedom from the obtained matches between the 144.9 impulse pattern and the pattern of the test shot from the grassy knoll. As Dr. Scheim noted, this is “akin to computing the volume of a cube as three by adding its dimensions” (Ibid.).

These two errors were how the NRC/NAS panel reduced the grassy knoll shot’s probability from 95+% to 77.7%. Of course, a 77.7% probability is still a rather high probability.

I have never seen a WC apologist comment on the fact that the Ramsey Panel admitted there was a 77.7% probability that the dictabelt’s 144.9 impulse pattern was caused by gunfire from the grassy knoll.

-- The NRC/NAS panel made no effort to explain the fact that the acoustical fingerprint of the grassy knoll test shot matched the acoustical fingerprint of the dictabelt’s 144.9 impulse pattern in all 26 points.

Queens College acoustical scientists Mark Weiss and Ernest Aschkenasy (two of the HSCA’s six acoustical experts) did a sonar analysis and found that all 26 of the echo patterns of the grassy knoll test shot matched with the 26 echo patterns of the dictabelt’s 144.9 impulse pattern (8 HSCA 27-29). 

Again, the Ramsey Panel didn’t even mention this remarkable correlation, much less try to explain it.   

-- The NRC/NAS panel also used faulty calculations to recalculate the probability of the timing-movement correlations identified by the four BBN scientists (four of the HSCA’s six acoustical experts) between the dictabelt’s impulse patterns and the impulse patterns on the recording of the Dealey Plaza test firing; however, they still ended up admitting there was a 93% probability that the correlations existed because the dictabelt was recorded by a microphone that was in Dealey Plaza during the assassination.

The BBN scientists said there was less than a 1% probability that the timing-movement correlations were the result of chance, based on the value of P<0.01 (i.e., probability less than 1%). The NRC/NAS panel argued that the BBN scientists had miscalculated, and that the BBN value of P<0.01 was actually P=0.07 (i.e., probability equals 7%).

The NRC/NAS panel claimed this meant the importance of the timing-movement correlations was “significantly reduced.” They didn’t bother to point out that a 7% probability that the correlations were the result of chance meant there was a 93% probability that the correlations were not the result of chance.

In the science of statistics, as the NRC/NAS panel members surely knew, if a correlation has a 93% probability of not being a coincidence, that means it is “extremely likely” the correlation is not a coincidence.

I have never seen a WC apologist mention this crucial admission.

BTW, subsequent research has proven that the BBN scientists’ calculations were correct and the NRC/NAS panel’s calculations were incorrect.

-- The NRC/NAS panel made no effort to explain the stunning presence on the dictabelt of N-waves characteristic of rifle fire. What makes the N-waves’ presence especially remarkable is that each of them is followed by a muzzle blast and then by muzzle-blast echoes, just as they should be. Moreover, a muzzle blast follows each N-wave at the correct interval, and the muzzle-blast echoes also follow the muzzle blasts at the correct interval.

Since the panel said nothing about the N-waves and their associated muzzle blasts and muzzle-blast echoes, they also said nothing about the fact that those N-waves occur only among the identified gunshot impulse patterns on the dictabelt, and only in the two impulse patterns that were recorded when the motorcycle’s microphone was in position to record the N-waves.

I spend considerable time documenting and discussing the N-wave evidence in my article “The HSCA’s Acoustical Evidence: Proof of a Second Gunman”.

-- The NRC/NAS panel made no effort to explain the remarkable windshield-distortion correlations documented by the HSCA’s acoustical scientists and confirmed by testing that they arranged with the New York City Police Department. The panel didn’t even mention these correlations. Since the panel didn’t even mention them, they didn’t comment on the fact the windshield distortions on the dictabelt occur only in those impulse patterns that were recorded when the microphone was in position to record them, and do not occur when the microphone was not in such a position.

Now, let’s review the NRC/NAS/CBA/Ramsey Panel errors that I’ve already discussed in previous replies:

-- The NRC/NAS panel miscalculated the duration of the alleged recording pause (their needle-skip adjustment) by nearly 100% because they didn't understand how the dictabelt machine worked.

-- The NRC/NAS panel originated the whole bogus heterodyne argument because they didn't understand the relationship of the transmitters and didn't understand that broadcasts can be superimposed from one channel onto another in real time.

It is revealing that Linsker and his colleagues abandoned the heterodyne argument in their 2005 response to Dr. Thomas’s research, because they recognized that their own poorly done PCC test disqualified both the Fisher and Decker transmissions as crosstalk if they used the heterodyne argument.

-- The NRC/NAS panel wrongly assumed that the differences in the energy in the Channel 1 heterodynes and the Channel 2 heterodynes proved that the Decker transmission must have been recorded in real time, because they didn't understand that a broadcast from one channel could have been superimposed on another channel in real time.

To this day, WC apologists cite the NRC/NAS/CBA/Ramsey Panel’s report as the definitive, end-of-story refutation of the acoustical evidence, when in fact it is nothing of the kind. It contains numerous major errors and does not even attempt to address several key items of evidence that support the HSCA’s acoustical findings.

[John Corbett]

As noted earlier, Dale Myers claims that the report produced by the NRC/NAS panel (also known as the CBA or the Ramsey Panel) is a “devastating critique” of the HSCA’s acoustical evidence. Not even close. Let’s take another look at this supposedly “devastating critique”:

-- As part of their recalculation of the probability that the dictabelt’s 144.9 impulse pattern was a shot from the grassy knoll, the NRC/NAS panel arbitrarily and wrongly assumed there were two degrees of freedom associated with the shooting position, but in fact there was only one degree of freedom, as MIT mathematician Dr. David Scheim pointed out:

For example, the critical Weiss-Aschkenasy conclusion of a 95-percent
probability of a grassy knoll shot was treated only in a sketchy three-page
appendix [in the NRC/NAS panel's report] that made one outright error -- there was only
one degree, not two, of freedom associated with the position of the shooter along
the grassy knoll fence. (Scheim, The Mafia Killed President Kennedy, 1992, p. 408 n 120)

-- In another facet of their effort to reduce the probability of the grassy knoll shot, the NRC/NAS panel used the curious, invalid approach of subtracting degrees of freedom from the obtained matches between the 144.9 impulse pattern and the pattern of the test shot from the grassy knoll. As Dr. Scheim noted, this is “akin to computing the volume of a cube as three by adding its dimensions” (Ibid.).

These two errors were how the NRC/NAS panel reduced the grassy knoll shot’s probability from 95+% to 77.7%. Of course, a 77.7% probability is still a rather high probability.

I have never seen a WC apologist comment on the fact that the Ramsey Panel admitted there was a 77.7% probability that the dictabelt’s 144.9 impulse pattern was caused by gunfire from the grassy knoll.

-- The NRC/NAS panel made no effort to explain the fact that the acoustical fingerprint of the grassy knoll test shot matched the acoustical fingerprint of the dictabelt’s 144.9 impulse pattern in all 26 points.

Queens College acoustical scientists Mark Weiss and Ernest Aschkenasy (two of the HSCA’s six acoustical experts) did a sonar analysis and found that all 26 of the echo patterns of the grassy knoll test shot matched with the 26 echo patterns of the dictabelt’s 144.9 impulse pattern (8 HSCA 27-29). 

Again, the Ramsey Panel didn’t even mention this remarkable correlation, much less try to explain it.   

-- The NRC/NAS panel also used faulty calculations to recalculate the probability of the timing-movement correlations identified by the four BBN scientists (four of the HSCA’s six acoustical experts) between the dictabelt’s impulse patterns and the impulse patterns on the recording of the Dealey Plaza test firing; however, they still ended up admitting there was a 93% probability that the correlations existed because the dictabelt was recorded by a microphone that was in Dealey Plaza during the assassination.

The BBN scientists said there was less than a 1% probability that the timing-movement correlations were the result of chance, based on the value of P<0.01 (i.e., probability less than 1%). The NRC/NAS panel argued that the BBN scientists had miscalculated, and that the BBN value of P<0.01 was actually P=0.07 (i.e., probability equals 7%).

The NRC/NAS panel claimed this meant the importance of the timing-movement correlations was “significantly reduced.” They didn’t bother to point out that a 7% probability that the correlations were the result of chance meant there was a 93% probability that the correlations were not the result of chance.

In the science of statistics, as the NRC/NAS panel members surely knew, if a correlation has a 93% probability of not being a coincidence, that means it is “extremely likely” the correlation is not a coincidence.

I have never seen a WC apologist mention this crucial admission.

BTW, subsequent research has proven that the BBN scientists’ calculations were correct and the NRC/NAS panel’s calculations were incorrect.

-- The NRC/NAS panel made no effort to explain the stunning presence on the dictabelt of N-waves characteristic of rifle fire. What makes the N-waves’ presence especially remarkable is that each of them is followed by a muzzle blast and then by muzzle-blast echoes, just as they should be. Moreover, a muzzle blast follows each N-wave at the correct interval, and the muzzle-blast echoes also follow the muzzle blasts at the correct interval.

Since the panel said nothing about the N-waves and their associated muzzle blasts and muzzle-blast echoes, they also said nothing about the fact that those N-waves occur only among the identified gunshot impulse patterns on the dictabelt, and only in the two impulse patterns that were recorded when the motorcycle’s microphone was in position to record the N-waves.

I spend considerable time documenting and discussing the N-wave evidence in my article “The HSCA’s Acoustical Evidence: Proof of a Second Gunman”.

-- The NRC/NAS panel made no effort to explain the remarkable windshield-distortion correlations documented by the HSCA’s acoustical scientists and confirmed by testing that they arranged with the New York City Police Department. The panel didn’t even mention these correlations. Since the panel didn’t even mention them, they didn’t comment on the fact the windshield distortions on the dictabelt occur only in those impulse patterns that were recorded when the microphone was in position to record them, and do not occur when the microphone was not in such a position.

Now, let’s review the NRC/NAS/CBA/Ramsey Panel errors that I’ve already discussed in previous replies:

-- The NRC/NAS panel miscalculated the duration of the alleged recording pause (their needle-skip adjustment) by nearly 100% because they didn't understand how the dictabelt machine worked.

-- The NRC/NAS panel originated the whole bogus heterodyne argument because they didn't understand the relationship of the transmitters and didn't understand that broadcasts can be superimposed from one channel onto another in real time.

It is revealing that Linsker and his colleagues abandoned the heterodyne argument in their 2005 response to Dr. Thomas’s research, because they recognized that their own poorly done PCC test disqualified both the Fisher and Decker transmissions as crosstalk if they used the heterodyne argument.

-- The NRC/NAS panel wrongly assumed that the differences in the energy in the Channel 1 heterodynes and the Channel 2 heterodynes proved that the Decker transmission must have been recorded in real time, because they didn't understand that a broadcast from one channel could have been superimposed on another channel in real time.

To this day, WC apologists cite the NRC/NAS/CBA/Ramsey Panel’s report as the definitive, end-of-story refutation of the acoustical evidence, when in fact it is nothing of the kind. It contains numerous major errors and does not even attempt to address several key items of evidence that support the HSCA’s acoustical findings.

YAWN

[Michael T. Griffith]

One falsehood you hear from many critics of the acoustical evidence is that determining the origin and timing of gunfire from acoustical recordings was a new and untested science in 1978. In point of fact, one of the reasons the Acoustical Society of America recommended BBN to the HSCA was that BBN acoustical scientists had real-world experience in determining the origin and timing of gunfire from a sound recording in the 1970 Kent State shooting incident.

Dr. James Barger, BBN's chief acoustical scientist, was one of the BBN scientists involved with analyzing the audio recording of the Kent State shooting at the request of the prosecution. Dr. Barger and his team used a combination of waveform physics, sound-speed calculations, vector triangulation, and an onsite reenactment to identify the location and timing of the numerous shots that were fired. They identified the shock waves and muzzle blasts of the rifle fire. By measuring the precise time-delay intervals between the arrival of the shock waves and the arrival of the muzzle blasts, the BBN scientists were able to mathematically calculate which National Guardsmen were the first to fire shots.

The BBN team isolated each individual pair of sound impulses (shock plus blast) and plotted them chronologically to determine the exact tempo of the shooting, showing that the gunfire lasted for approximately 13 seconds. This allowed the BBN experts to determine that the shots were not fired in a single, simultaneous blast, but rather in a rapid, overlapping sequence. And, using vector triangulation and sound-speed calculations derived from the shock wave-muzzle blast intervals, Dr. Barger and his team were able to determine the gunfire's distance from the microphone and to establish that the gunfire came primarily from the crest of Blanket Hill, where the National Guardsman were positioned.

Does any of this sound familiar?

BTW, the BBN team's acoustical analysis in the Kent State case was so solid and impressive that it was not only admitted as evidence in the trial but was stipulated by the defense to be correct (5 HSCA 645). As most here know, defense lawyers don't like to stipulate to the correctness of damaging scientific evidence unless the evidence is beyond dispute.

Finally, I should point out that, not surprisingly, by 1978 Dr. Barger had already established himself as a recognized expert in applied acoustics, sound scattering, and sound reverberation, and had been a research fellow at Harvard University's Acoustics Research Laboratory before being hired by BBN. Before working at Harvard, he worked as a sonar scientist in the U.S. Navy's Underwater Sound Laboratory. By 1978, he had also had numerous papers published on acoustical science. After the HSCA investigation, Dr. Barger continued to have papers and articles published on acoustical science, including the following:

"Boomerang Mobile Counter Shooter Detection System" (2005, Proceedings of The International Society for Optical Engineering)

"Systems and Methods for Determining Shooter Locations with Weak Muzzle Detection" (2007, which earned a U.S. patent for BBN [by then Raytheon BBN]). "This technology of muzzle detection and system, applied in direction finders, acoustic wave reradiation, instruments, etc., solved the problems of inability to determine the range (distance) of the shooter, inaccurate derived distance information, and inability to determine the distance between the sensor(s) and the origin of the shockwave, so as to improve the disambiguation of the shooter's trajectory solution."

"System and Method for Identifying a Muzzle Blast Using a Multi-sensor Total Energy Approach" (2008, which earned a U.S. patent Raytheon BBN)

"System and Methods for Detecting Shooter Locations from an Aircraft" (2013, which earned a U.S. patent for Raytheon BBN)

[John Corbett]

If the acoustic evidence is so solid, why didn't anybody see a gunman on the GK?

[Michael T. Griffith]

If the acoustic evidence is so solid, why didn't anybody see a gunman on the GK?

Umm, because he fired from a concealed position behind the fence on the knoll.

Moreover, as I have pointed out to you before when you have argued against a grassy knoll shooter:

-- Several witnesses saw gun smoke coming from the area behind the fence on the knoll identified by the acoustical evidence as the location of the gunman.

-- We have hard photographic evidence that confirms the eyewitness accounts of seeing gun smoke on the knoll, i.e., the Wiegman film, which shows a small cloud of smoke hanging in the air near the fence on the knoll.

-- Several witnesses smelled the pungent odor of gunpowder on and near the knoll right after the shooting.

-- Two witnesses saw a man running from the grassy knoll into the railroad yard seconds after the shots were fired.

-- Dozens of witnesses in the plaza (at least 58) said they heard shots fired from the grassy knoll.

We still see lone-gunman theorists repeating the argument that those witnesses merely heard echoes of the sixth-floor gunman's alleged three shots. In his superb 1998 book Cover-Up, mathematician Stewart Galanor explains why the echoes argument is invalid:

Echoes are caused by sound bouncing off large, hard surfaces. . . . There are no buildings on the knoll or overpass that would have reflected sound back to confuse witnesses in Dealey Plaza. Beyond the knoll the terrain is flat with railroad tracks, while the knoll is covered with grass, shrubs, and trees that absorb sound. If there were any echoes, they would have been caused by the sound of rifle fire from the knoll echoing off the Book Depository (Cover-Up, p. 76).

-- Dozens of witnesses rushed up the grassy knoll right after the shooting because they believed shots came from there.

-- Seconds after the shooting, Sheriff Bill Decker ordered his officers to seal off the area of the railroad yard behind the knoll and the triple underpass: "Have Station 5 to move all men available out of my department, back into the railroad yards there in an effort to try to determine just what and where it happened down there, and hold everything secure until the homicide and other investigators can get there."

-- Seconds after the shooting, Chief Jesse Curry ordered his officers to check the area of the triple underpass: "Get a man on top of that triple underpass and see what happened up there!"

-- William Newman, a combat veteran, said he heard a shot come from behind him on the knoll and that he heard the whiz of the bullet as it passed near him. As someone who heard bullets whiz above him in the Army, I know exactly what Newman was describing.

-- Abraham Zapruder, before he knew what he was supposed to say, told the Secret Service on 11/22/63 that "the position of the assassin was behind Mr. Zapruder" (CD 87). Zapruder was standing on the pergola on the knoll, so the area behind him would have been very close to the spot identified by so many other witnesses and by the acoustical evidence.