Car Ride Before Entering the Lab Increases Precision in Listening Tests 2015-01-2285

Subjects who are well aware of what to judge commonly yield more consistent results in laboratory listening tests. This awareness may be raised by explicit instructions and training. However, too explicit instructions or use of only trained subjects may direct experiment results in an undesired way. An alternative is to give fairly open instructions to untrained subjects, but give the subjects a chance to get familiar with the product and context by, for example, riding a representative car under representative driving conditions before entering the laboratory. In this study, sound quality assessments of interior sounds of cars made by two groups were compared. In one group subjects were exposed to the same driving conditions that were later assessed in a laboratory listening test by taking them on a ride in one of the cars to be assessed, just before entering the laboratory. In the other group subjects made the laboratory assessments without prior car riding. In the laboratory, sound quality was assessed for binaurally recorded interior sounds of cars reproduced through headphones. The results showed that even though average sound quality assessments in most cases were the same for both groups, the variances were significantly smaller for the group where subjects had been taken on the car ride before the listening test. A conclusion is that being exposed to the sounds in the right context just before the listening test, e.g. by riding a representative car under representative driving conditions, can increase the precision in laboratory sound quality assessments.