A Different Sound With Each Use Of A Blade?

This past Tuesday I finally used for the first time my 1912 with a GEM SS. Great shave, a couple weepers, but no problem. It was my first real run with a single edge. Wednesday I palm stropped the same blade and put it into my new G-Bar. A milder shave, no problems. Thursday, more stroking and back into the 1912. Some cheek irritation, but that was to be expected as I've still yet to master the SE. This morning, the same routine, but I stuck with the 1912. Another great shave, and no problems.
However, the "sound" of the shave was really different. The first thres shaves on this blade, I got that thick, resonant sound of the blade with each swipe. Today that sound was "tinny" and it sounded like the blade wasn't loaded properly. I ad to check twice to make sure, and yeah it was okay. It just seemed off, and almost like the blade was much thinner. The shave was still great, but it felt weird having that tinny sensation on the fourth shave as opposed to the first three.
Am I wrong to expect a more rigid blade like the SE to last longer than a DE? I always swapped out a DE blade after three uses and am now wondering if the same is to be expected of SE blades.

I have no explanation for the change in audible feedback, assuming that you're not experimenting with different angles, etc.

I can tell you that I got a smooth comfortable shave this morning using a Gem stainless steel blade on shave #15.

I cannot guarantee that you will get 15 shaves per blade, but you should definitely get more than you were getting from DE's.

--Bob

Thanks Bob,
Upon further review about the only routine that I deviated from for the fourth shave was not using glycerin soap during my pre-shave shower this morning. I'll give it a go, properly, tomorrow morning for shave five. 15 shaves on one SE blade? That's what I'm shooting for with my single edge razors.
It seems like I need to not sweat the small stuff, after all it was a good shave...it just sounded weird (weird also that I never really noticed the "sound" before while using DE's)

I take great care to silence my environment to hear and judge shave progress from the sound.

The glycerin may be the issue. Your beard would be better hydrated with glycerin, leading to a difference in sound from less hydrated stubble.

Shave five this morning, including the use of glycerin soap during my preshave shower. Yup, that "thick" sound a single edge blade I missed, and fretted over, was back. Funny how that works. It also helped that it was one of those relaxing Saturday morning shaves.