Among the great mysteries is why drivers of vehicles that have the most decrepit mufflers feel compelled to drive with the gas pedal pinned to the floor.

At least they do when they pass my house along Auburn Avenue, with the apparent intention of imitating an artillery barrage at Verdun in 1916.

This compulsion seems to reach its apex just when I am ensconced in the deepest and most pleasant embrace of REM sleep.

Precisely at 4:40 a.m. on one recent day.

(I made sure to note the time on my bedside digital clock, in case I later suspected myself of exaggerating.)

Any time between midnight and dawn is popular, though.

These high-decibel drive-bys annoy me year-round.

But being jolted awake, wondering if a burglary or a meteor strike is in progress, strikes me as especially grievous during summer.

We open our bedroom window to usher in the comparatively cool air that usually settles overnight in our mountain valley. The flimsy screen that admits the refreshing breeze is, unfortunately, no obstacle to the fusillade from a muffler that, if it is actually attached to the exhaust manifold, must resemble a hunk of rusty Swiss cheese.

Unlike the occasional bark of a distant dog, or the peal of a passing freight train’s whistle, either of which in certain cases can evoke a pleasant nostalgia, the metallic cacophony of a mangled muffler is pure noise pollution.

It is the internal combustion equivalent to a 2-year-old who, denied dessert or some other essential item, lets loose a squeal that could shatter fine crystal.

I don’t mean to imply that volume, when it comes to a vehicle’s exhaust note, is inherently obnoxious.

I quite like the deep rumble of a well-tuned V-8, the staccato beat of an engine equipped with a custom long-duration camshaft.

This mechanical melody is the product of perfectly machined parts that move at dizzying speed, separated by a thin film of oil that is replaced regularly.

Of course I don’t want a dragster running the quarter-mile in front of my house at 3 a.m.

But the percussion that invades my bedroom represents the opposite of precision.

It is the sound of oil changes done with the frequency of the Olympics.

Of slipped clutches and abused brakes.

I understand that maintaining a vehicle is expensive.

Food and shelter are far more important than exhaust pipes.

But the drivers, who are much closer to the noise than I am, ought to recognize that when they rev the engine to its redline in the darkest hours, they’re almost certainly rousing people from sleep.

On a recent night it was a natural noise, not a manmade one, that awakened me.

The thunderstorm that the National Weather Service had forecast had arrived just about on time — 3:30 a.m.

I regretted the lost slumber but I judged the deal a fair one because the storm, with its rain and wind, replaced the warm, stale air in the bedroom at least as efficiently as any fan.

The cool breeze wafting through the window carried the inimitable scent of rain on sage, something the clever makers of artificial air “fresheners” can never replicate.

As late as 11 a.m. I was shivering as I sat in front of my computer, several feet from another open window.

I could have donned a jacket but I chose to revel in the goosebumps beading my forearms.

The air didn’t feel autumnal, exactly.

That typically happens, at least for me, along toward the end of August or in September.

But after enduring the most severe heat wave in Baker County history, a stretch of torrid days that started July 5 and continued, with brief and modest interruptions, through Aug. 12, a day when the temperature didn’t reach 80 by mid-morning was as refreshing as sipping a cold beer after a few hours of heavy work outdoors.

I thought I might be able to keep the bedroom window at least partially closed during the coming night.

Not that plain glass is much of a barrier against the aural assault of a rig that constantly sheds its exhaust system, leaving a trail of shards of rusted metal in its boisterous wake.