Can I get this straight please? You say that you don't know the procedure, I link to a video OF the procedure, and ask only if your unshared idea will beat the test, and you're treating me like i'm the one with comprehension difficulties?
Would that be a correct summation?
You might want to search for some of inreb's other posts ...
When I had my bike tested, the person doing the testing had a tachometer that he could attach to determine your RPM in case your bike wasn't equipped with one.
Was that the acoustic analyzer?
There is no guaranteeing that your bike's primary sound frequency (that this thing would be analyzing) would correlate properly to the RPM. It could conceptually show half, equal, or double pretty easily. For example, a very well balanced inline four would have exhaust pulses at twice the crank rotation frequency and if the carbs/throttle bodies were well balanced and the exhaust system was a symmetrical 4 into 1, there would be no occurrence of a half-crank-rotation frequency. A single will have exhaust pulses at half crank rotation speed. An inline-four with slightly out-of-balance carbs would have a half-crank-rotation pattern imposed on top of the double-crank-rotation pattern. And so forth ... It's easy for someone who knows a thing or two about engines to shoot holes in how that thing works.
Mechanical tach? No dice. My bikes all require fairing removal to get to the crank end covers, and most of them are "wet" (oil pumped/splashing/circulating) under those covers.
Ignition pick-up? Lots of newer models are coil-on-plug; there is no accessible high-voltage signal that an inductive pick-up could access. In some cases (and I own one example), gaining access to the spark plugs and re-assembling the bike afterwards is an 8 hour job, and you cannot run the engine in the condition that allows access to the spark plugs (you have to take the throttle body assembly off ...)
OEM tach? Lots of them are inaccurate. Of course, they generally read high, which actually is in the bike owner's favor since 5000 rpm on the tach would be something less in reality, but still, it's not a certified instrument.
Of course, a lot of the primary noise offenders have a separate exhaust pipe for each cylinder, an uneven firing pattern, and readily accessible high-voltage leads to the spark plugs ...