Meeting Topic: Tutorial Seminar on Acoustics (two days)
Moderator Name: Akira Nishimura (Section Chair), Atsushi Marui (Section Vice Chair), Kazuhiko Kawahara (Education), Kazuya Nagae (Education), Akira Omoto (Education), Tetsuya Nakazawa, Masayuki Mimura, Shinji Koyano, Masataka Nakahara
Speaker Name: Akira Nishimura (Tokyo Univ. of Info. Sciences), Akira Omoto (Kyushu Univ.), Atsushi Marui (Tokyo Univ. of the Arts), Bike H. Suzuki (SONA / MQA), Hisaharu Suzuki (Evixer), Kazuho Ono (NHK STRL), Kazuma Hoshi (Nihon Univ.), Masataka Nakahara (SONA / ONFUTURE), Shinji Koyano (Koyano Sound Lab.), Toru Kamekawa (Tokyo Univ. of the Arts), Yoshitaka Tamura (Studio Equipment), Yuko Watanabe (Tokyo Denki Univ.)
Meeting Location: Senju Campus, Tokyo University of the Arts, Tokyo, Japan
The eighth annual seminar which started in 2010 was held in 8th and 9th September.
The seminar consists of 12 classes which cover most of the areas on acoustics and audio technologies. In the seminar, professionals give lectures which should be usually learned in universities as special knowledge expertise. The titles of lectures and timetable are shown below.
This year, a total of 61 people attended the seminar, and four people joined AES this time.
The seminar has one Master Class which introduces the latest technologies on acoustics and audio. This year, it was entitled "Recording and Reproduction of 3D Sound Field" It was chaired by Dr. Masataka Nakahara from SONA Corp. / ONFUTURE Ltd, and two presenters introduced several strategies for capturing and reproducing 3D sound field. This year, the proposed methods were somewhat concentrated outside of the precise wave field reproduction and synthesis.
This class was defined as a prologue for AES international conference 2018 entitled "Spatial Reproduction, Aesthetics and Sciences", which will be held in Tokyo on September 7th-9th, 2018.
Firstly, Prof. Toru Kamekawa introduced standard microphone arrangement technique including height location, which was suitable for new surround loudspeaker arrangement such as 22.2.
Prof. Akira Omoto then introduced the trial of obtaining directional information of sound by using Hedgehog shaped 24ch narrow directional microphone array. This microphone array was used to obtain not only incoming sounds themselves but also directional impulse responses.
Lastly, Dr. Masataka Nakahara introduced a method of obtaining directional information of reverberation from arbitrary solid angles by using sound intensity responses, which were calculated from impulse responses at closely located and orthogonally arranged microphones.
These directional responses were used as filter coefficients of reverberator for reproducing loudspeakers of corresponding directions. The last two methods can be interpreted as a realization of spatial reverberator.
The similarity and difference of the proposed methods were examined with the recording and reproduction of solo violin performance with 22 channel loudspeakers.
The audience listened to the live performance of violin and 22ch playback of all kinds of reproduced sounds created by different methods.
Finally, impressions and the problems of new techniques are discussed and shared by audiences and lecturers.
Written By: Akira Omoto
