Friday, September 30, 3:15 pm — 4:45 pm (Rm 409B)
Sungyoung Kim, Rochester Institute of Technology - Rochester, NY, USA
P15-1 In-Vehicle Audio System Distortion Audibility versus Level and Its Impact on Perceived Sound Quality—Steve Temme, Listen, Inc. - Boston, MA, USA; Patrick Dennis, Nissan Technical Center North America - Farmington Hills, MI, USA
As in-vehicle audio system output level increases, so too does audio distortion. At what level is distortion audible and how is sound quality perceived as level increases? Binaural recordings of musical excerpts played through the in-vehicle audio system at various volume levels were made in the driver’s position. These were adjusted to equal loudness and played through a low distortion reference headphone. Listeners ranked both distortion audibility and perceived sound quality. The distortion at each volume level was also measured objectively using a commercial audio test system. The correlation between perceived sound quality and objective distortion measurements are discussed.
Convention Paper 9651 (Purchase now)
P15-2 Effect of Presentation Method Modifications on Standardized Listening Tests—Julian Villegas, University of Aizu - Aizu Wakamatsu, Fukushima, Japan; Tore Stegenborg-Andersen, DELTA SenseLab - Hørsholm, Denmark; Nick Zacharov, DELTA SenseLab - Hørsholm, Denmark; Jesper Ramsgaard, Widex - Lynge, Denmark
This study investigates the impact of relaxing presentation methods on listening tests by comparing results from two identical listening experiments carried out on two countries and comprising two presentation methods: the ITU-T P.800 Absolute Category Rating (ACR) recommendation and a modified version of it where assessors had more control on the reproduction of the samples. Compared with the standard method, test duration was reduced on average 37% in the modified version. No significant effects of the method used on the ratings of codecs were found, but a significant effect of site on ratings and duration were found. We hypothesize that in the latter case, cultural differences and instructions to the assessors could explain these effects.
Convention Paper 9652 (Purchase now)
P15-3 Can We Hear The Difference? Testing the Audibility of Artifacts in High Bit Rate MP3 Audio—Denis Martin, McGill University - Montreal, QC, Canada; CIRMMT - Montreal, QC, Canada; Richard King, McGill University - Montreal, Quebec, Canada; The Centre for Interdisciplinary Research in Music Media and Technology - Montreal, Quebec, Canada; Wieslaw Woszczyk, McGill University - Montreal, QC, Canada; George Massenburg, Schulich School of Music, McGill University - Montreal, Quebec, Canada; Centre for Interdisciplinary Research in Music Media and Technology (CIRMMT) - Montreal, Quebec, Canada; Martha de Francisco, McGill University - Montreal, QC, Canada; CIRMMT Centre for Interdisciplinary Research in Music Media and Technology - Montreal, QC, Canada
A new type of listening test for testing very small impairments in audio systems is proposed using audio engineer participants and a mix matching task based approach. A pilot test was conducted in an attempt to reveal perceptual differences between WAV (44.1 k-16 bit) and MP3 (256 kbps) encodings of the same musical material. The participant mixing data was analyzed and trends in the data generally coincide with the hypotheses. Several factors were also found that can influence participant accuracy and speed in completing this type of test: age, experience (production, musical, listening test), and preferred genre for audio work.
Convention Paper 9653 (Purchase now)