Sound quality assessment using binaural technology

Abstract: This licentiate thesis contains experimental work about the use of binaural technology for assessment of sound quality. Binaural technology aims to measure sound in the way compatible with human hearing. For that purpose artificial head with the microphones in the position of the ears is used. First experiment aims at assessing sound quality of heavy-duty diesel engine which, runs on different fuels. In this experiment instead of artificial head optimum stereo signal technique (Jecklin disk) is used. The results show that engine running on different fuels possesses different sound quality characteristics. One of the purposes of binaural technology is to recreate sound field with correct spatial position of sound sources. However, the spatial position of sound sources is not always correctly recreated. Sound source localization errors occur. The second experiment aims at assessing the effect of localization errors on sound quality judgments of heavy-duty diesel engine noise. The results show that localization errors can influence localization judgments.The following step is to try to eliminate localization errors in binaural recordings. Therefore the third experiment assesses the influence of the short training session, priori to listening to binaurally recorded sounds, on localization performance. Results show that training can help to avoid localization errors for certain acoustical conditions.