Listening tests have been carried out to quantify the significance of binaural auralization over monaural auralization in accordance with the acoustic properties of the enclosure. To this end, acoustic rendering of three different rooms were generated based on synthesized monaural (two channels with the same audio material) and binaural room impulse responses. The auralizations were evaluated by means of subjective tests using headphones with non-individualized equalization. Parameters, such as localization, spatial impression and realism, were taken into consideration to determine the relevance of providing binaural information for the auralization of a given room. The analysis of the data has been conducted following a statistical approach based on ANOVA and Pearson correlation. The results indicate that spatial perception is strongly dependent on the acoustic characteristics of the rooms and on the listening condition of the audio material. Furthermore, as expected, advantages of binaural rendering in terms of source localization was also confirmed.
The present work consists of a statistical study of the monaural (lateral-reflection fractions and level) and binaural acoustic parameters (inter-aural cross-correlation coefficients) that evaluate the amount of early and late lateral acoustic energy encountered in 9 performance halls in Andalusia (southern Spain). Hall volumes range between 6,163 m3 and 34,594 m3 and all enclosures are used for presentations of symphonic concerts and other music performances. The majority of these venues are located in provincial capitals of the community and often constitute the only premises in the city where symphonic concerts can be held. The acoustic parameters under study here were derived from impulse responses analyses using a sine-sweep signals which were generated and processed by WinMLS 2004 software in the octave- band frequency centred from 125 to 4 kHz, and all parameters were spectrally averaged according to the ISO 3382-1 standard. A comparison is presented of monaural experimental results as a function of source- receiver distance with the prediction of Barron’s revised theory for concert halls, and the analyses of the acoustic parameter results are carried out in terms of their respective just noticeable differences: at the many microphone positions for the two source positions on stage, for the spatial distribution of seats in the audience zone relative to the central axis (for left- and right-hand sides) of the rooms, and for the presence of the orchestra shell on stage. Results reveal that the orchestra shell propitiates a perceptible decrement in the values of the early lateral energy fraction and an increment in the late lateral level at the audience seats. In addition, a regression study reveals that the two kinds of measures of laterality, monaural and binaural, are correlated when the hall-average data is considered, but they remain uncorrelated when all individual positions are used. Likewise, the ranges of variation of the acoustic parameters found in these halls are narrower than those specified in the ISO 3382-1. The paper concludes with a discussion on the relationships of hall-average data of the five parameters with eight geometric and acoustic variables.
There are typically two systems in use for sound reinforcement in open areas: the central, “wall of sound” system with speakers localized at the sides of the stage, and the zone system, in which additional speakers are introduced to obtain a uniform sound pressure level throughout the area of listening. In the past two decades the line array systems gained great popularity. The main purpose of their use is to obtain a uniformly distributed sound level throughout the listening area in order to achieve good speech intelligibility. The present paper aims to present an alternative and original method of sound reinforcement in open areas which is in contrast to the above solutions. This new method allows achieving a uniformly distributed sound pressure and good speech intelligibility in the area of interest, and also allows to gain spatial sound impression that accompanies sound reproduction in concert halls. Another advantage of the proposed system is the reduction of the sound level outside the area of interest, i.e. reduction of the noise level outside the area of listening.