Use of Psychoacoustic Metrics for the Analysis of Next Generation Computer Graphic Card Noise

Abstract

The continuing challenge to deliver performance improvements in computer graphic cards has long since progressed to the point of requiring finned, passive, cooling devices to dissipate the heat generated by the graphics processing unit (GPU). The heat flux generated by further improvements now exceeds that dissipation capacity so that passive cooling can no longer provide adequate cooling the GPU. The dissipation rates required by the latest generation of designs can be delivered by forced air cooling of finned heat sinks. The concurrent challenge to the industry is to provide this cooling while minimizing the noise generated by these cooling fans. A significant aspect associate with this problem is missed if one only considers the problem to be a one-dimensional sound level issue. From a consumer’s perspective, the perceived quality of the noise emitted takes precedence over what traditional acoustical analysis techniques of this fan noise may imply. Here, psychoacoustic or sound quality metrics, may be a more applicable analysis tool as it provides the quantification of these qualitative human impressions. The present study investigates the validity of using several psychoacoustic metrics for the analysis of fan cooled computer graphics card noise. Using experimentally measured fan noise from three different cooling fan designs, a sound quality analysis was performed using loudness, sharpness, roughness, fluctuation strength, prominent tone and articulation index. A discussion and comparison of measured results using traditional analysis techniques is also included. It was found that some of the metrics proved more useful than others as an analysis tool for this specific noise source. A discussion of the applicability of the various sound quality metrics along with justifications is presented.