Dear Sonderführer Storing,
As Roselle and Scearce pointed out in their 2020 article, a loud and unexpected sound that comes from behind you and over your head is the hardest to locate.
https://www.acsr.org/post/estimating-occult-timing-of-surprise-gunshot-sounds-in-silent-film-via-observed-start-of-human-vol?fbclid=IwAR12nBxuwJNQk5YVStu8jKxu-wnyIprRvzLSpJ7mLurtZpzj7DMU0LQeof8
Especially, one would think, in the echo chamber known as Dealey Plaza.
D'oh!
-- Tom
I am not sure why you think that Roselle and Scearce's speculations on how difficult it might be to recognize source direction of a gunshot sound are of any value. They even admit that this comment was speculative.
The fact is that human brains rely on both ears to determine sound source. The brain detects time differences between the arrival of a sound wave at each ear to determine lateral position of the source. Our ability to detect that a sound is coming from behind instead of the front is facilitated by the shape of our ears.
Here is the Wikipedia page on Sound Localization and here is a
paper dealing with experiments on people that may be of interest. I expect that ability to determine direction of sound is an important survival mechanism that has been highly conserved over millions of years.
The problem with detecting an actual source arises when there are nearby reflective surfaces that cause multiple wave fronts to arrive at the ears at slightly different times. Nevertheless, most witnesses, particularly those near the corner of Elm and Houston, had little difficulty in determining the direction of the source. For example, Dearie Cabell instinctively looked directly up from where she was facing (which was to her right toward the right front seat) and saw the rifle in the 6th floor window as they were already making the turn. She said (7 H 486):
Mrs. CABELL.. I heard the shot, and without having to turn my head, I jerked my head up.
Mr. HUBERT. Why did you do that?
Mrs. CABELL. Because I heard the direction from which the shot came, and I just jerked my head up.
Mr. HUBERT. What did you see?
Mrs. CABELL. I saw a projection out of one of those windows. Those windows on the sixth floor are in groups of twos.
Mr. HUBERT. In which window did you see the projection?
Mrs. CABELL. I have always been a little confused about that, but I think it was the first window.