Acoustic Evidence

[Phil Sanders]

New here.  Can someone please direct me to on this forum or explain the apparent contradiction that J. Thompson uses acoustic evidence in his book, The Last Second in Dallas,  and the previous work that claims to debunk the Dictabelt recordings. Thanks.

[Michael T. Griffith]

New here.  Can someone please direct me to on this forum or explain the apparent contradiction that J. Thompson uses acoustic evidence in his book, The Last Second in Dallas,  and the previous work that claims to debunk the Dictabelt recordings. Thanks.

I address the attacks on the acoustical evidence in my article "The HSCA’s Acoustical Evidence: Proof of a Second Gunman in the JFK Assassination".

By "the previous work that claims to debunk the Dictabelt recordings," I'm guessing you're referring to the NRC/NAS panel's critique of the acoustical evidence. The panel, aka the Ramsey Panel, did not include a single acoustical scientist, and virtually their entire case rested on the debunked claim that the Decker "hold everything" transmission was crosstalk and that the transmission proved the sound impulses were recorded 30-60 seconds after the shots were fired.

Dr. Thompson arranged for new research by BBN acoustical scientists from 2015-2018 that refuted the NRC claim about Decker's transmission and that verified that the Fisher "I'll check" transmission is actual crosstalk and that it proves the sound impulses were recorded during the shooting. He discusses this new research at length in Last Second in Dallas. Two BBN acoustical scientists wrote appendices in Thompson's book.

Also, it's worth noting that the NRC/NAS panel admitted (as obliquely as possible) (1) that they found a 93% probability that the timing-movement correlations identified by the BBN scientists between the dictabelt and the recording of the test firing in Dealey Plaza occurred because the dictabelt recorded gunfire in Dealey Plaza, and (2) that they found a 77.7% probability that the 144.9 impulse pattern, identified by Weiss and Aschkenasy as gunfire from the grassy knoll, was in fact gunfire from the knoll. You'll notice that critics of the acoustical evidence never, ever deal with this fact.

See also the following:

https://www.maryferrell.org/arch/essays/debugging-bugliosi

https://www.maryferrell.org/arch/essays/bike-with-the-mike

https://www.maryferrell.org/arch/essays/sabato-sonalysts-sophistry

https://www.maryferrell.org/arch/essays/overview-and-history-of-acoustical-evidence-1

Another excellent analysis of the acoustical evidence is Dr. David Kaiser's lengthy discussion on the subject in his highly acclaimed book The Road to Dallas (pp. 377-387).

And you might find this discussion helpful:

https://educationforum.ipbhost.com/topic/29269-understanding-and-appreciating-the-hsca-acoustical-evidence/

My signals intelligence training in the Army included courses on radio wave propagation, modulation, the effects of automatic gain control, RF theory, the electromagnetic spectrum, etc. I don't claim to be an acoustical scientist, but I know more about the subject than your average Joe.

[John Corbett]

The claim that the acoustics evidence found on the Dictabelt recording shows a fourth shot has been thoroughly debunked in so many ways. The following is as good as any:
 
https://www.jfkfiles.com/jfk/html/acoustics_2.htm

Going to the homepage will also give you access to Dale Myers 3D animation of the shooting.

[Michael T. Griffith]

The claim that the acoustics evidence found on the Dictabelt recording shows a fourth shot has been thoroughly debunked in so many ways. The following is as good as any:
 
https://www.jfkfiles.com/jfk/html/acoustics_2.htm

Going to the homepage will also give you access to Dale Myers 3D animation of the shooting.

The sources I cite in my reply refute every single criticism presented in the article you cite, Dale Myers' article. You'd know this if you'd bothered to read the links I provided. If you had just read my article on the acoustical evidence, you'd know that Myers' article is woefully inadequate and misleading.

And for the benefit of other readers, be advised that Dale Myers' research has been proven to be erroneous, if not fraudulent. As just one example, to make his ridiculous SBT trajectory analysis work, Myers falsely assumes that Connally's back wound was 3.0 cm wide, when in fact it was only 1.5 cm wide, the same width as JFK's rear head entry wound.

For a good critique of some of the problems with Myers' bogus research, see the uber-cautious Pat Speer's demotion of Myers' SBT nonsense:

https://www.patspeer.com/chapter12canimania

Here is just a little bit of what Speers says about Myer's SBT simulation:

. . . his deception regarding the single-bullet theory is simply inexcusable. He would have to know that when people see computer simulations they believe the proportions are consistent from angle to angle—otherwise it’s just a cartoon. By changing the body shape of Kennedy to accommodate the bullet trajectory through his body, and by shrinking Connally 20% or more to accommodate the bullet trajectory in the car, Myers moved on up to the high rent neighborhood of Thomas Canning: deliberate deceptionville.

For a critique of Myers' error-riddled hatchet job on the Tippit shooting, see my article "Did Oswald Shoot Tippit?"

It says much that you would rely on someone like Myers to get your information on the acoustical evidence. Have you even read the studies that the BBN and Queen's College acoustical scientists submitted to the HSCA on the acoustical evidence?

Myers obviously hasn't read them, because he doesn't say a word about any of the evidences they present, such as the windshield-distortion correlations, the timing-movement correlations, and the presence of N-waves and their echoes in the correct order and timing. Nor does Myers say a word about the NRC/NAS panel's admissions about the timing-movement correlations and their own finding of a high probability (77.7%) that the 144.9 impulse pattern is gunfire from the grassy knoll.