Speaker
Description
The psychoacoustic metric of roughness is key to many acoustic evaluations. Although several calculation methods are available, each method yields slightly different roughness values for different signal and modulation types. In addition, the practical interpretation of roughness values is often unclear due to the limited knowledge of absolute and just noticeable difference thresholds, especially for complex technical sounds, which are typically subject of roughness analysis. To broaden the empirical basis on thresholds of roughness, a listening test was designed and conducted. Using a constant-stimuli procedure, thresholds were determined for both simple reference signals, including amplitude modulated pure tones and broadband noise, and more complex synthesized drone sounds. Thresholds were derived for three commonly used roughness calculation methods (ECMA 418-2, Zwicker and Daniel & Weber). Although threshold values depended on signal type and calculation method, low roughness values were associated with low thresholds, whereas higher roughness levels resulted in higher thresholds.