What you are saying is that the audio experts hired by the HSCA investigators were looking at random noise and just happened to find noise patterns on the actual police recording made during the shooting that matched the echo patterns made from the test shots AND they also got the timing between shots on the audio recording to MATCH the times between shots seen in the Zapruder film.
What does that statement mean? Look at the figure again. If you have good enough resolution you can see that some of the noise spikes are numbered, those noise spikes generally MATCH the TIMING of the noise spikes seen on the actual recording. This figure shows just ONE of the shots, they found matching echo patterns for each of the shots (for a total of five shots). 
The audio experts were familiar with echo correlation analysis because during the Kent State shooting investigation, they wanted to know WHO fired the first shot. By determining WHERE the first shot was fired from the investigators were better able to determine what happened.
How do you determine where shots were fired from if you only have an audio recording? A shot makes a LOUD very short duration noise that radiates outward in all directions. When the noise energy hits large objects such as buildings, it is reflected off and arrives at a microphone at a later time than does the initial noise spike because reflected waves have to travel further. The audio experts did NOT rely on trying to identify a "BANG" on a recording as most people would, they looked for echo patterns with amplitudes high enough above the ambient noise level to be repeatable (i.e. they fired many test shots from two locations in Dealey Plaza where it was thought based on witness testimony that a gunman might have been located). The timing of the echo patterns would be unique for each of the shooting locations and for each of the microphone locations (the microphone was located on a moving motorcycle).
So what do we have?
1. A study done by audio experts that showed the echo patterns from test shots fired from two locations generally matched what was seen on the actual police radio recording
2. The times between shots on the Zapruder film match the times between shots seen on the audio recording.
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#1 is difficult to understand and VERY difficult to actually do. #2 is very easy to understand and very easy to do.
Here's a question for you: If it is so easy to determine that 4.8 seconds is the time between two of the shots in the Zapruder film AND the police audio recording, how come Vince Bugliosi's book RECLAIMING HISTORY did NOT address that seemingly significant bit of information? In fact, look at all the books, all the documentaries you wish to explore and you won't find that information anywhere (except for what I have written). How is that possible? This is probably the most written about "mystery" in history and 4.8 seconds has been hidden?
The answer is yes, it was buried. Once you understand how this was hidden from the public you will be well on your way to understanding what happened during the shooting.
