NBC NEWS - With gas prices reaching new highs more and more people are purchasing hybrid cars, but some folks are making noise about hybrids, claiming the energy efficient vehicles don't make enough noise.

"It takes a little getting used to, but most things do," says Gerald Wagner, who drives a Toyota Prius Hybrid.

One of the features Wagner likes most about his car is that, aside from the great gas mileage, it's so darn quiet.

So when he heard about an idea to actually add artificial engine noise to hybrid cars like his, he balked!

"I love the quiet part.  It's novel," says Wagner.  "I mean, most of the cars in this parking lot look the same and feel the same.  This is different."

It's an issue big car manufacturers never saw coming.

Or in this case, never heard coming.

Hybrid cars run so silently, at times, that in states like California and Maryland they're talking about laws to make them noisier.

The problem, say some activists, is that children playing or even blind people ready to enter crosswalks, can't hear hybrid cars coming.

They point to several cases where people have stepped right out in front of them, nearly getting hit.

Hybrids have created all sorts of new challenges.

Local fire-rescue workers, for example, have had to learn new techniques to avoid getting zapped by those powerful hybrid energy cells at accident scenes.

Toyota sales manager Stu Stewart says back up cameras and sensors have already helped reduce accidents in all kinds of vehicles, and if someone decides some artificial engine noise will help hybrids, he thinks it would make a great option.

"I think any safety equipment they can think of to put on any car is a great thing."