Kazuma Hoshi

Speech privacy at community pharmacies

To identify practical ways to assess privacy protection at counseling area in community pharmacies, we conducted site-visit investigations at 84 community pharmacies including on 10 telephone interviews, and internet questionnaire survey on 160 patients. In the typical Japanese community pharmacies, space is small, the counseling area is open, and there are many patients who are waiting until their name is called. In that situation, busy and noisy and loose concentration, patients must try to accurately grasp medical information, and pharmacist are also working in the same situation. At the site-visits, we asked about aural or visual privacy issues and performed a psychological experiment to determine whether the patient-pharmacist conversation could be heard from the waiting seats for patients. At the internet questionnaire, we asked about counseling environment at community pharmacies. Responses to the site-visit investigation and internet questionnaire survey revealed that privacy-related problems were...

Evaluation of spatial impression of sound field in a concert hall based on the sound intensity using musical sounds

Spatial impression is one of the most important factor for evaluating sound fields in concert halls. Objective indices, such as the lateral energy measures, for evaluating the spatial impression are standardized in the ISO-3382. These indices can be measured by using a figure-of-eight pattern microphone. On the other hand, details of spatial information of sound field can be depicted by measuring instantaneous sound intensity in the sound field. However, thus far, there is no index using the sound intensity. In this study, first the relationship between the existing objective indices and the sound intensity is examined. In particular, the existing objective indices are redefined based on the sound intensity. Secondarily, some objective indices are newly defined by using the sound intensity. These intensity-based indices can basically be calculated by using the sound intensity of impulse responses in a room. Third, potential of measuring the intensity-based indices by using musical sounds is examined. We i...

A fundamental study of evaluating sound fields in performance spaces based on equal tempered scale

Generally, the reverberation times, energy decay curves, directional characteristics, and so on are analyzed in 1 octave bands or 1/3 octave bands for evaluating acoustic conditions in performance spaces. The center frequencies such as 1000 Hz are defined by engineering implication. However, these center frequencies are not always adequate for evaluating performance spaces because music is basically composed of musical scale like the equal tempered scale. Therefore, it is thought that it is reasonable to use center frequencies based on the equal tempered scale in order to evaluate performance spaces. Based on this idea, we calculated reverberation times and energy decay curves for 1/12 octave bands at which center frequencies are set by using the equal tempered scale. Directional characteristic of reflected sounds is an important factor for evaluating spatial impressions in performance spaces. Therefore, we measured the directional characteristics based on sound intensity in the 1/12 octave bands. Moreove...

Room Acoustics Simlation

This chapter shows examples of numerical simulation results on various sound fields in the interior of buildings and vehicles, such as auditoria, large space with seating rows, reverberation rooms, vehicle cabins, and small space with partitions. In each section, the features and problems of each sound field are introduced, and numerical modeling schemes of the simulation and the calculated results of the sound fields are described and illustrated. Some of the calculated results are compared with those obtained by other methods or measured ones to discuss the applicability and efficiency of the analysis method.

Theoretical Modeling of Room Shape for Ray Tracing Simulation

With the recent developments in computer-aided design (CAD) technology, the detailed modeling of shapes has become routine. However, it is well known that low-frequency sounds do not propagate in detail-oriented models of rooms in the way that is predicted by geometrical acoustic simulations. Therefore, rough models of room shapes are commonly used and scattering coefficients are set for each material in this kind of simulation. However, scattering coefficients are difficult to use for creative room shape design, because scattering coefficients need to be measured in advance. Thus, we propose a new method for ray tracing simulations that can be used in place of the scattering coefficient method. This paper presents a discussion of methods for constructing the appropriate room shape for the analyzed frequency from a detail-oriented model of a room.

Introduction to special sessions and the SS chairs/co-chairs

IEEE GCCE welcomes Special Session proposals which are related to up-to-date and cross-field topics. As the results of reviews, GCCE 2013 decided the following eight sessions to be held in the final program. We are glad to introduce the SS chairs who propose the interesting hot topics and their session abstracts.

Spatial impressions from late overhead reflections in concert halls

It is known that not only late lateral reflections but also late overhead reflections contribute to listener envelopment (LEV) which is one of the perceptive factors in the spatial impression of sounds in a concert hall. This paper describes results of psychological experiments which are intended to clarify differences between spatial impressions of the late overhead reflections and that of the late lateral reflections. The results are the following: (1) Late overhead reflections have a different acoustic effect from late lateral reflections. (2) Late overhead reflections increase not only LEV but also overhead sound image (OSI). (3) Late lateral reflections contribute mainly to horizontal listener envelopment (HLEV). (4) If OSI is increased in addition to HLEV, a listener feels vertical listener envelopment (VLEV).

Quantitative evaluation of characteristics of an auditorium shape in horizontal cross section

The room shape of an auditorium is often classified as a ‘‘shoe‐box type,’’ ‘‘fan‐shape type,’’ ‘‘round type,’’ ‘‘surrounding (vineyard) type,’’ or other shape. The surface diffusivity index (SDI), which is an evaluation index of surface irregularities, has been proposed by Haan and Fricke, but the SDI is based on visual surveys of photographs or drawings [Appl. Acoust. 51(1), 53–69 (1997)]. Clarification of the relationship between an auditorium’s shape and its acoustic characteristics would be simplified if the auditorium shape were understood objectively rather than subjectively. Therefore, in this study, we tried to objectively obtain characteristics of a room shape in horizontal cross section using an elliptic Fourier descriptor, which can detect the periodicity of a two‐dimensional contour. Room shapes were expressed as spatial frequency characteristics calculated from their Fourier descriptors. Based on them, we can understand the amplitude of irregularities and their scale. In addition, by using principal component analysis, it is possible to understand, quantitatively, the main differences of room shapes in horizontal cross section.