Kazuhiko Kawahara

Extraction of applause from a sound field for ambient transmission in a live viewing system

Live performances are increasingly appreciated using popular commercial audiovisual transmission systems, such as live viewing systems. A reality enhancement method for live viewing had been proposed. This paper describes an applause sound extraction method for automation of applause sound transmission and a simulation experiment using the sound source recorded live at the venue to assess the applause sound extraction performance. We used an adaptive filter to emphasize applause sounds and extracted them using signal amplitude information. The experimental evaluation showed that the applause sound was extracted almost correctly from the performance sound source under various conditions.

Advanced technical listening training program at Kyushu University

This presentation introduces the Advanced Technical Listening Training (TLT) program at Kyushu University. TLT is a systematic training program designed to improve auditory sensitivity; it consists of discrimination and identification tasks for a wide variety of acoustic features (e.g., frequency, sound pressure level, and spectrum pattern). The TLT II class (i.e., the advanced TLT program) provides training in identification of reverberation time, quantization bit depth, mixing level balance, and spectral slope of harmonic tones. TLT facilitates improved understanding of acoustic theory and phenomena, and psychoacoustics.

Design and performance evaluation of a stereo sound reproduction system with a complementary distributed mode loudspeaker

This paper proposes an effective method to use a Distributed Mode Loudspeaker (DML). DMLs are loudspeakers with strong diffusion properties. In this paper, we proposed a sound reproduction system with a DML. The sound field generated by the proposed reproduction system is measured by the index of diffusivity. As a result, it is concluded that the sound field generated by the proposed reproduction system has a higher diffusivity when compared with a conventional reproduction system. The proposed system also demonstrates strong results with respect to the influence of the chambers acoustic boundary on sound quality.

Impression measurement of three different types of loudspeakers' sound field

Recently, some new implementations of panel form loudspeakers were proposed. Some of them have quite different radiation characteristics compared with dynamic loudspeakers. Especially Distributed Mode Loudspeaker (DML) has diffused property of radiation. But the subjective impression of this property was needed to investigate. In this paper, 39 adjective and adjective phrases were selected for impression measurement. Two of dynamic loudspeaker models, a DML and an electrostatic loudspeaker were used for this impression measurement. As a result of median test, DML gave the impression of wider sound fields, spatial sense, depth sense and blurred sound fields.

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.

Effectiveness of technical listening training in Department of Acoustic Design of Kyushu University

What is the professional listening? Sound/Acoustic Professionals listening categorized into three phases. The ability to discriminate between different sounds. The ability to correlate the auditory difference with the physical properties of sounds. And the ability to imagine the proper sounds when given the acoustic properties of the sounds. The ability can be trained through listening training. Through trainings, trainees can share their auditory experience. The shared experience reinforces trainees to express their auditory impression with coherent words. And the use of coherent words supports smooth communication in their group. This word coherency is also the professional listening ability. In this paper, as a listening training, Technical Listening Training in Kyushu University was described. And we evaluated learning effects of training with average correct answer ratio among trainees. Trends of increasing correct answer ratio with training times were observed. We could show the effects of Technical...

Technical listening training: Systematic training program designed to improve auditory sensitivity

Technical listening training is a systematic training program designed to improve auditory sensitivity. Through this program, students can obtain the necessary auditory sensitivity before gaining work experience on the job. The type of auditory sensitivity acquired through experience depends of course on the occupation. In contrast, technical listening training provides wide varieties of experiences, so that students can obtain auditory sensitivities associated with various fields and easily adapt to new auditory environments. Technical listening training was developed at the Department of Acoustic Design of the Kyushu Institute of Design. The program has been improved and is still included as part of the curriculum of the Department of Acoustic Design. The present demonstration exhibits the concept of technical listening training as well as its practical application at the School of Design, Kyushu University.

Superdirectivity design for a sphere‐buffled microphone array

For the signal extraction from a diffuse sound field, the superdirecitonal microphone array seems to be more stable and more effective than the noise canceling microphone array system. In this research, for the sphere‐baffled microphone array (SBM), the superdirectivity characteristic was designed by the frequency domain beamforming method and the complex least mean square algorithm. The frequency domain beamforming is a method for a broadband beamforming. There is a possibility of improvement of the directivity frequency characteristic. The SBM is an array which was embedded 36 elements on the rigid diffractive sphere of 8.84 cm radius. An advantage of SBM is its isotropy. When the directivity characteristic was fixed for a definite direction, only the shift coefficent can be used to change the mainlobe direction. This idea can be easily generalized into the three‐dimensional mainlobe control. In a typical design calculation, for the beamwidth of −3 dB, 30° was achieved at the frequency 2 kHz. This characteristic is comparable to that of a larger size microphone, which is called a shotgun microphone.