The other day, I'm rowing through the gears pleasantly, and it dawned on me what our 3-Tapper sounds like. (3-Tapper because it doesn't have enough power to bang ... it just taps.)
It sounds nicer than an inline 4. What it sounds like, while not as loud, is a 2-Stroke Detroit diesel engine.
I guess it makes sense, we have 3 cylinders turning fast. Where a 2-Stroke diesel is likely turning slower, but has an ignition stroke twice as often as our 4 stroke. Leaving the vastly different engines sounding similarly.
Below is an example of the sound. I just found this on a cursory search, I'm sure there are better examples. But I liked this one because the dude driving the truck acts and drives a lot like me as I'm leaving work for the day.
Note when he coasts it off rolling backward, the engine is actually running ... in the opposite direction as normal, so it smokes out the intake!