Rome’s famous Trevi fountain welcomes 10.5 million visitors a year. What is it about water spraying out of a decorative source that gets people hot and bothered? Lisa Aiken, the interior designer behind Terra Firma Design, chalks it up to the soothing sound and trance-like effect of watching moving water.

In the early aughts, when she ran a garden store in Bloor West village, shoppers often stopped by simply to take in the aural pleasure. “I had all the fountains running,” says Aiken. “And I had a lot of them.

It allowed people to hear what they sound like.” Getting the gurgling sound right is essential, adds Aiken, whose firm specializes in outdoor spaces. You want it pleasurable, not noisy.

“The first fountain I ever got was massive, before I even owned a store,” she says. “I put the water in and turned it on. It was like a hose hitting the ground.

It was awful.” Layering rocks inside the fountain to dampen the sound did the trick, and Aiken was hooked. These days, linear styles are her thing.

“I like a trough-like fountain because it’s more of a modern look,” she says. “It can be built into a raised surface, so you don’t see any plugs or tubing and you can adjust the height of your spouts to control the water and flow.” Chris Marchese, general manager of Marquis Gardens, supplies water features, accessories and statuary to homeowners in Toronto and the GTA.

These include features like waterfall spillways that can tart up a swimming pool, or st.