by Nick Kettman
Dave Bogema of Bruel and Kjaer spoke to the Chicago Section on December 5, 2006, on the
topic of Sound Quality Measurement. Mr. Bogema currently works as an application specialist
for B&K in Detroit and is responsible for product sound quality measurement and analysis
products. Twenty-three local audio professionals attended the event.
Mr. Bogema began by giving his definitions of the terms “noise” and “sound.” In the context of
sound quality measurement, “noise” is usually undesired and often regulated to avoid hearing
damage, noise pollution, etc. “Sound,” on the other hand, is a normal and often desired
characteristic of a product. Many manufacturers now engineer their products for pleasant sound
quality because users take cues from the sound to determine overall product quality. For
example, even if the motor in a vehicle’s powered seat is functioning normally, it can be rejected
by the manufacturer on the basis of certain subjective sound qualities, such as grinding or pitch
modulation, which might lead the user to believe that the motor is broken or underpowered.
One goal of Sound Quality Measurement is to relate objective measurements with subjective
evaluations. The measurement process often starts with an audio recording of the product under
test which undergoes subjective evaluation by humans as well as objective evaluation by audio
analyzers or computer software. Based on the results of these evaluations, product designers and
engineers can troubleshoot the problems and make design changes. In order to optimize this
process, a precise audio recording is required. By correlating the objective results with the
subjective results, the objective tests can be improved, enabling faster and more reliable results
with a lesser need for human test subjects.
Mr. Bogema pointed out that much of the advanced sound quality work being done today is
driven by the automotive industry, one of the first industries to incorporate engineering for sound
quality in the product design process. He completed his presentation by offering several
examples of products, both automotive and non-automotive, which have been engineered for
sound quality. One example is a golf putter. It was discovered that the sound of a putter affected
a golfer’s perception of the “feel” of the club.