Ford Sound Engineers Sometimes Turn Up the Volume

NEW YORK -- The automotive engineers that deal with sound devote most of their time to eliminating NVH, for "noise, vibration and harshness" inside cars and trucks. But in some cases, especially with certain kinds of engine sounds, they may work instead to turn up the volume.

"Noise is unwanted sound," said Mark Vojtisek, Ford Motor Co. manager of integration, in a presentation here today. "We don't always want bland and boring."

Vojtisek is responsible for defining the right blend of feel and sound in new Fords like the redesigned 2010 Ford Taurus. Talking sound with Vojtisek is like talking snow with the proverbial Eskimo with 100 words for snow.

Unwanted kinds of noise include road noise, wind noise and the noise made by bumps in the road. Engine noise includes "moans," Vojtisek said. Desirable sounds, if they're executed correctly, can include sharply defined door-closing sounds, the "purr" of an engine at low revs, or the "addictive" sound of an engine at high revs, according to Vojtisek.

In addition to scientific measurements for all of the above, Ford uses consumer "sound juries" to gauge their reactions to sounds.

Competitors use similar methods to pursue similar aims. Bentley, for instance, last year went out of its way to engineer the exhaust system in the 2009 Bentley Continental Flying Spur Speed to produce a distinctive, low-frequency "burble" when you lift your foot off the gas.

In Ford's case, Ford discovered that its turbocharged "EcoBoost" engines are a little "too" quiet. EcoBoost uses a turbocharger and gasoline direct-injection to produce more power from a smaller engine. The net effect is a V-6 with the power of a V-8 but the fuel consumption of a non-turbo V-6.

Vojtisek said the fan blades inside the turbocharger serve to block some of the "good" engine noise, so Ford made changes to the air intake to reintroduce a greater volume of sound.

"It's like a musical instrument," he said. "People like the right sound."

Photo: Ford