One evening a couple of months ago, I was headed back to work after dinner and, waiting for a red light to change, I let my mind wander.

Just before the light changed to green, I took a quick look around and was surprised to see a car sitting next to me.

As it pulled away, I chided myself for zoning out so much I didn’t hear the car approach.

As it happened, I caught up to the vehicle at the next light, and it finally dawned on me that it wasn’t just my own spaciness that allowed the vehicle to sneak up on me. It was a hybrid, and it obviously was in electric mode as it approached the light at which I was stopped.

And electric cars can be awfully quiet.

I have to admit, the incident spooked me a little.

I figure hearing is the second-most important sense — behind sight — to a bike commuter intent on, well, living. Of course, that’s not as profound as it seems, since smell, touch and taste don’t do much to keep the miles piling up.

But I rely heavily on my ears.

I can tell when cars are approaching and how close they are. I can tell if they’re accelerating or decelerating. Sometimes I can even tell if the driver is angry or impatient. Some cyclists claim they can tell the kind of car that is approaching by the sound it makes, but I’m not that discerning.

Sometimes, I’ll admit, I won’t even turn around before, say, a left-hand turn because I just know that silence behind me means there’s no internal-combustion engine gaining on me.

But these stealthy hybrid/electric vehicles change the game a bit.

Don’t be mistaken: I’m a fan of hybrids and electrics. I wish I could afford one. In a perfect world, my next –or even third! — car would be an electric Smart Car, powered by solar panels on my garage.

And I’m opposed to pollution in all forms: air, light and, yes, noise.

So the thought of a vehicle that’s environmentally friendly and quiet — hmm, sounds kind of like a bike — works for me.

As long as it doesn’t crush me like an opossum.

I happened across a news item that shows I’m not alone in my disquiet about the quiet.

It seems Japan has launched a government review on whether to add a noise-making element to its near-silent hybrids after vision-impaired groups called them dangerous.

“Blind people depend on sounds when they walk, but there are no engine sounds from hybrid vehicles when running at low speed” and on the electric motor, a transport ministry official said.

The official said there had been no decision on what kind of sound should be used, only that it should “induce a response of caution.”

As much as I’d like to know a vehicle is gaining on me, the thought of adding a noise-maker — deer whistles, anyone? — strikes me as odd, and I reckon few people would be willing to put up with an unnecessary belling-of-the-cat noise just to announce their presence to a tiny minority.

Regardless, I find myself riding even more cautiously these days.

If only I could smell ’em coming.