Introduction of auditory filter into evaluation of characteristics of small enclosures

Abstract

Physical measures, which are useful for evaluating small enclosures such as studios and car cabins, are examined. Especially, auditory filtering using Zwicker’s loudness model is introduced for calculating the measures. Most current measures used in evaluating the large sound field such as concert halls are based on measured or calculated impulse responses. Instead, the music signals of some genres are used in this study. Using the auditory model, the amount of information can be reduced, even when complicated signals are used as stimuli: the signals are convertible to information in 25-bark bands. Correspondence of such physical quantities and subjective judgments are considered from the viewpoint of sound-field similarity. Subjects are asked to judge the similarity of two successive sounds whose frequency characteristics are modified artificially using the equalizer. The analysis results obtained using the auditory filter were compared with the subjective evaluation. Results indicate that analysis using the auditory filter can yield fairly good correspondence with the subjective evaluation, especially in a middle frequency band. Regarding the low-frequency band, the degree of correspondence depends on the musical genre. Expanding the effective frequency bands is an important theme of our ongoing research.

Sound field evaluation using auditory filter: Application of dynamic compressive gammachirp filter

“…On the other hand, sound field evaluation for a rather small and dead room condition such as a recording studio is seldom investigated. We have continuously tried to establish an effective evaluation scheme for such a small and dead room condition [1,2]. This study is one in a series of such trials.…”