iRacing.com Sound Team Captures Real-Life Motorsport Action Placing the Aural on Par With the Visual: Pops of an Exhaust Pipe, Gravel in the Wheel Well and Fiberglass-Meets-Wall Come Together in High-tech Training Tool for Racers

BEDFORD, MA (4 April 2007) From the high-pitched whine and buzz of on-load acceleration to the pops and clicks from off-load deceleration, every car has a voice. Recreating every possible behind-the-wheel scenario as well as recording, uploading and digitally mapping that voice is the ongoing project for the iRacing.com Motorsport Simulations sound team.

Many racers will attest that the aural cues are just as important as the visual ones when driving a car on-track at the limit. Whether the machine is a 150-horsepower, 1,250-pound formula car or a 750-horsepower, 3,400-pound stockcar, a racer must be able to understand what the car is "saying" as it communicates valuable performance information through a range of sonic indicators.

"Our goal is to create the ultimate training tool for racers, providing valid, relevant seat-time when they can't get to the track," said Scott McKee, vice president of marketing at iRacing.com. "In order to achieve that we need to give the driver as accurate and complete a sensory experience as we can, which means applying the same level of focus and discipline to gathering and accurately replicating sound data as we do with the visual data and other physical parameters."

The most basic auditory cue is engine noise, which for the trained ear can be as accurate a marker of shift points as the tachometer without having to take valuable fractions of a second to look at the gauges. Bumps and vibrations transmitted from the racing surface through the chassis are also useful indicators, allowing the perceptive racer to locate his or her car on the track as accurately as any sight picture and precisely time steering and other control inputs. Tire noise, too, can be crucial to driving at the limit in certain types of cars. The difference between the way a tire sounds at the optimum slip angle and one that has gone past the point of peak performance can be the difference between a win and a DNF (Did Not Finish). Likewise, being able to discern threshold braking from wheel lock-up may be all that separates a successful pass from a smoky slide and a visit to the pits to change flat-spotted tires.

The iRacing.com sound team recently spent some time in the field recording several cars for the new simulation. The team captured engine sounds from a Skip Barber Formula 2000 at Sebring International Raceway in Sebring, FL. They then visited nearby Orlando Speedworld where, with help from retailer Russ Thomson and his 17-year-old, state champion son Brandon, they picked up sounds from a Legends Car. Finally, the team headed north to Phoenixville, PA, to record several production-based racecars on a chassis dynamometer at the Phoenix Motorsports shop of Joe Aquilante. iRacing.com sponsored the Phoenix Motorsports Team at the 2006 SCCA Runoffs.

Each of the locations presented a specific set of challenges to the team. At Sebring, ambient noise from activity related to the Twelve Hours of Sebring necessitated coordination of the recording sessions with quiet periods on the track and a bit of cooperation with nearby spectators. At Orlando, the team confronted wind noise issues as they recorded at speed on track. The solution involved creative placement of tiny microphones throughout the engine bay and inside the car to minimize the surface area of the microphones and ensure cleaner sound capture. At the Phoenix Motorsport race shop, the acoustics of the building in which the dyno was housed were less than ideal. The answer, again, was technology this time larger, high-fidelity microphones that produce the best sound quality when wind baffling isn't a concern.

Ambient sounds will also be created by the iRacing.com sound team to simulate some of the more white-knuckled moments in motorsport hitting the wall and skidding, rolling and peeling on all kinds of different surfaces. Crash sounds are recreated and recorded in junkyards using large machines to smash car parts together with varied intensities fiberglass hits concrete, steel hits pavement, etc. Hearing the tire skid off the pavement, the spatter of gravel in the wheel well and the way the gravel eventually dissipates brings the entire experience to life. This level of accuracy in sound recording supports the cutting-edge scanning, graphic rendering quality and sophisticated physics modeling that are already a part of the iRacing.com simulation.

Up to this point, the iRacing.com production team had been using placeholder sounds and will now be working to program in the results from the recordings made over the past weeks. As the sounds are recorded, they are uploaded to a proprietary mixing system that slices the sound recordings into short bits that can then be mixed and randomized for the most realistic and varied sound experience.