People walking past the Origins store yesterday got a sonic surprise, as their steps triggered a medley of sounds including bird calls, waves and even a nonexistent barking dog.

The sound presentation, called Sonic Pass, was designed by musician Christopher Janney and relied on audience participation to create a motley medley of sound.

Pedestrians were asked to stroll, strut, jump or crawl, across the sidewalk in front of the Brattle Street store. Their actions triggered infrared sensors which activated synthesized sounds.

The result was interesting and worthwhile, passersby said.

"I think it's great, and neat--what a fabulous idea," said Princeton student Caroline Bumb.

Other participants were even emotionally moved by the display.

"I found it was spiritual, enlightening and powerful. I feel relived," said Stephan Gallo.

More Wailing

Not all were quite so ecstatic. Several infants were frightened by the loud noise and added to the electronic cacophony with some wailing of their own.

Janney said Sonic Pass is part of a series of sound-art presentations around the world.

For the past 15 years, Janney said, he has taken his act "not to clubs but on the streets." Previous displays have taken place in the New York subway, the Spanish steps in Rome and the steps of the Justice Department in Washington, he said.

His next presentation will take place in the MBTA, he said.

Yesterday, women on walkers, men in suits, dogs, cats and even a squirrel crossed the invisible infrared beams of Sonic Pass, but children seemed to be the most excited by the display.

"Adults walked by and didn't even notice, while the children were immediately fascinated," said Origins spokesperson Catherine C. Marcus '92.

But while Marcus was surprised at the younger spectators' enthusiasm, Janney said he expected kids to be the most receptive.

"This reinforces the notion that the younger you are, the more you realize your surroundings," said Janney. "I actually designed the project to bring out the creative play in all of us."