![]() 1(b), the early specular reflections were modeled up to second order. A diffuse reflection path can propagate in any direction from the reflecting surface while the specular reflection is as from a mirror. The reflections that occur in the room can be roughly categorized either as specular or diffuse. In the early part of the response most of the reflection paths can be seen separately, although they might overlap temporally and sum together. Each peak in the figure represents a single reflection path starting from the direct sound that has not undergone any reflection. ![]() Such responses can be considered to consist of three separate parts: direct sound, early reflections, and late reverberation. Often, the time-energy response is computed as a first step and an impulse response is synthesized from the former. A corresponding time-energy response from a simulation might look like as in Fig. BACKGROUNDĪ typical room impulse response, as measured in a room, or obtained by room acoustical simulation, is illustrated in Fig. VI, we summarize different modeling techniques and compare their capabilities. V, we focus on techniques that propagate the sound energy to surfaces as an intermediate step and then gather the response at the listener from those surfaces. Section IV presents techniques in which the actual sound propagation paths play a major role, whereas in Sec. There are several different methods of categorizing these techniques, but we divide them into two separate groups, path- and surface-based techniques. Similarly, a mathematical framework for all GA modeling techniques is presented. The required conceptual models for sound propagation in air and for reflections from surfaces are introduced in Sec. In addition, various landmarks in the adoption of GA modeling techniques in practice are discussed. Section II presents the early history of room acoustic modeling, starting from the pre-computer era and subsequently introducing the first steps toward computerized modeling. Similarly, a detailed comparison of computational performance of different techniques has been left out of this article. These capabilities establish the baseline for achievable accuracy, but the final accuracy and ability to match measurement results depend on a sufficiently large number of factors such that a detailed discussion on accuracy is beyond the scope of this overview. In particular, the focus is on the capabilities of the techniques. ![]() The focus will be on the theoretical aspects of the various methods, which means that a wealth of practical aspects regarding input data acquisition, data uncertainty, and use of the techniques, among others, is omitted. We attempt to provide a comprehensive overview, specifically of geometrical acoustic-based methods, within the limits of a journal paper. Similarly, the computation of room acoustic attributes and the actual sound rendering component of auralization 1 and related signal processing techniques, such as artificial reverberation 4 or binaural processing, 5 are beyond the scope of this overview. The modeling of structure-borne sound is excluded from this overview because the related noise propagation models are typically quite different from the techniques discussed here.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |