News 17-01 (No.349)
Issued : January 25, 2017
Yamato City Cultural and Creative Complex “Sirius” Opens
By Fumiaki Sakamaki
A new cultural and creative complex named Sirius opened in Yamato City, Kanagawa Prefecture on November 3, 2017. November 3 is the annual Japanese Culture Day national holiday, an appropriate day for the opening of the new facility.
<< Overview of the New Complex >>
(Photo: courtesy of Shinozawa Architectural Photography Studio)
Main Hall Interior Stage View
(Photo: courtesy of Shinozawa Architectural Photography Studio)
Main Hall Interior Auditorium View
The Odakyu Enoshima Train Line and Sagami Railway intersect at Yamato City’s Yamato Station where the new complex was built as a revitalization project for the neighborhood east of Yamato Station. The complex comprises performing arts and cultural spaces (specifically, a Main Hall, Sub Hall, Multipurpose Space and a Gallery), a public library, a lifelong learning center (including a practice studio, lecture room, meeting room and Japanese tatami room) and an indoor, children’s play area. Facing the street on the ground level is FM Yamato Radio Station’s broadcasting studio with windows through which pedestrians can see radio announcers and DJs performing live radio programs. On the second floor of the building is a new Yamato Tenmangu Shinto shrine, replacing the shrine that stood on the land before the Sirius complex replaced it.
The name “Sirius” was chosen for the complex in addition to its official name of “Yamato City Cultural and Creative Complex” because this is the name of the brightest star in the Canis Major constellation. The people of Yamato City wanted to make an association between the brightest star in a heavenly constellation and their new cultural center, which they hope will “outshine” other facilities and entertainment destinations in the area and become the beloved destination of the city’s residents.
The companies that participated in the revitalization project did so under a Japanese system that enables private businesses to invest in a development project in return for arrangements related to ownership of the land and contracts to run and maintain the new facility. For this project, AXS Satow Inc. served as the architect and Shimizu Corporation as the general contractor. For the operations of the new complex, a designated management organization “Yamato Mirai” was formed and is being overseen jointly by Suntory Publicity Service Ltd, TRC Library Service Inc., and BorneLund Corporation. Nagata Acoustics joined the project from the conceptual architectural planning phase and provided the full range of acoustical consulting services through the design and construction phases, as well as acoustical measuring and evaluation services at project completion.
<< Sound Isolation for the Sirius Project >>
The Sirius complex is located on a site that is a 5-minute walk east of Yamato Station. The complex’s outdoor promenade is situated on land that is directly above the Sagami Railway’s subway tracks (and the tracks are about a 10 m. (33 ft) distance from the complex’s exterior walls). The U.S. Naval Air Facility and Japan Maritime Self-Defense Force Air Base in Atsugi are located approximately 1 km. (0.6 mile) from the complex.
Because of these site conditions, preventing solid borne noise and vibration transfer from the Sagami Railway subway line and isolating interior spaces from the sound of airplanes flying overhead were major goals of our sound isolation work on this project. Soon after we joined the project team, we conducted investigations to measure the vibrations from Sagami Railway subway trains and the noise levels from both airplanes flying overhead and nearby roads and vehicular traffic. With this data in hand, we considered how to mitigate vibration and noise from the external sources. Based on our measurements, we predicted that in the hall’s location, without any mitigation, the level of solid-borne noise and vibration from the Sagami Railway subway would be on the order of NC-35 and the noise from airplanes on the order of NC-35 to NC-40. Both these values greatly exceeded the level of quietness that we wanted to achieve in the room, which was between NC-20 and NC-25. Accordingly, we gave both the entire Main Hall and Sub Hall anti-vibration and anti-noise structural designs that included the use of floating floors of anti-vibration rubber. In addition to these measures for the 2 halls, to the extent feasible, we also maximized the implementation of anti-vibration and anti-noise structural designs for the multipurpose space, the practice room, lecture room and broadcasting studio.
Regarding the anti-vibration and anti-noise structural design of the Main and Sub halls, the project’s overall structural engineers strongly requested that the design be able to withstand 3.3 G of lateral shaking in the case of an earthquake. For this objective, we were requested to include small gaps in the anti-vibration and anti-noise layer design where ceiling and walls intersect. To prevent a reduction in the efficacy of the sound isolation performance, we added a double layer of rubber at each small gap. As a result, in addition to achieving the desired level of sound isolation, we addressed the need to withstand the specified lateral force of an earthquake.
After the completion of the project, we confirmed in both the Main Hall and Sub Hall that we achieved the desired level of sound isolation and quietness with regard to noise and vibration from the Sagami Railway subway trains. Also, airplane and vehicular traffic noise cannot be heard at all in the halls.
For the west tower of the complex, we specified a new external window sash that we developed for the windows of the library and indoor children’s play space to ensure sound isolation from airplane noise. We began by using a sash with the best rating for sound isolation properties. The sash alone has a sound isolation performance (sound transmission loss) greater than 33 dB. We then developed a specific application for use with double-pane glass windows of the Sirius project.
<< Main Hall’s Room Acoustics Design >>
The Main Hall seats 1,007 persons on a main floor and single balcony tier and is designed as a multipurpose hall. We designed a movable sound reflection panel system for the stage so that the hall can be used both for classical music concerts and converted to a different configuration for other uses. When the sound reflection panel system is stored, the stage becomes appropriate for drama, symposia, ceremonies and other amplified events.
For classical music performances, we designed the hall’s acoustics to have both abundant sound reverberation and sound clarity. To do this, we focused on obtaining sufficient spatial volume in the hall and the effective production of early sound reflections.
The height of the stage proscenium measures 12 m. (39 ft) from the stage floor, enabling us to achieve an interior configuration of continuous unity between the stage and the audience seating. To promote effective sound reflections that reach both the performers’ area on stage and the center seating of the audience seating area, we installed some 150 sound diffusers on the rear wall of the stage, the sides of the sound reflection panel system and the side walls of the audience seating area of the hall. Each sound diffuser is angled out and slightly downward from where it is attached to a wall. To make these sound diffuser elements easy to fabricate, we designed them with a base shape made of 1.6 mm. (0.06 in.) iron sheet metal. On the undersides of the diffusers we affixed a double under layer of 10 mm. (0.4 in.) fiber-mixed gypsum board and for the finishing material on the visible side of the sound diffusers, we affixed 6 mm. (0.2 in.) Di-Noc calcium silicate boards.
The reverberation time in the main hall is 2.2 seconds (in an empty hall) and 1.7 seconds (in a fully seated hall) when the stage’s sound reflection panel system is in use, and 1.5 seconds (in an empty hall) and 1.2 seconds (in a fully seated hall) when the stage is set up with its proscenium curtain configuration. (Empty hall values are based on measurements taken in the hall and fully seated hall values are calculated. All values are at 500 Hz.)
<< Sub Hall’s Room Acoustic Design >>
Sub Hall Interior
(Photo: courtesy of Shinozawa Architectural Photography Studio)
The 272-seat Sub Hall is a multipurpose hall with the movable and storable audience seats. We installed a retractable sound reflection panel system around the side walls of the stage area. When the hall’s seating is set up in rows and the sound reflection panel system is extended along the walls, this hall can serve as a small-scale venue for classical music concerts, as well as for drama performances and lectures. When the seating is stacked and stored, and the sound reflection panel system is retracted, this flat-floored hall can be used for events that include participant dancing and a broad variety of other events and occasions.
The Sub Hall has a basically rectangular footprint. On the walls of the stage and audience area we installed vertical rib finishing of 3 different widths in random periodicity. This wall treatment is intended to prevent flutter echoes from the otherwise parallel walls.
The Sub Hall’s reverberation times with audience seats are 1.1 seconds and 0.9 seconds in the concert hall configuration and are 0.7 seconds and 0.6 seconds with the stage curtain (in empty and fully seated halls, based on measured and calculated values, respectively). When configured as a flat-floored, multipurpose event space with the seating and sound reflection panel system stored, the hall’s reverberation time is 1.6 seconds (in an empty hall, based on measured value).
<< Sirius’ Opening Performances >>
On Saturday evening, January 7, 2017, I attended a New Year Concert performed by the Vienna Volksoper Symphony Orchestra in Sirius’ Main Hall. The evening’s production included performances by soprano and tenor soloists and 2 ballet dancers in addition to the music of the Vienna Volksoper Symphony Orchestra. The performances with orchestra, singers and dancers delivered an appropriately gala experience for a New Year’s concert. The sounds of the hall’s acoustics were truly satisfying.
When I arrived at the Sirius complex, the library and the café at the building’s entrance were filled with women and men of all ages enjoying the new facility. In addition, a line of people were waiting to visit the Tenmangu Shrine in keeping with the Japanese New Year tradition. I felt that the new complex has already blended into the lives, customs and cultural enrichment aspirations of the city’s residents. I hope that the complex continues to shine as brightly as the Sirius star in the heavens to become a beloved destination of people of Yamato City.
The Yamato City Sirius Complex’s website can be found at: http://yamato-bunka.jp/
Are Accessible Passenger Sounds Effective at Train Stations?
By Nobuhiko Hattori
Sound notification loudspeaker at Station A
Sound notification loudspeaker at Station B
If you travel by train in Japan, you may have noticed a “pin-pon” electronic sound at the wickets of various stations. Japanese commuters who pass through train stations daily mostly ignore the sound and may not even recall if they hear it, but this accessible passenger sound notification is broadcast at most Japanese train stations. The recurring sound is intended to indicate to visually impaired train passengers the location of the wickets through which passengers must pass to enter and exit the station. In this article, I will discuss the current implementation and some related issues.
<< The Rationale for Accessible Passenger Sound Notifications >>
Transportation systems and certain kinds of buildings install and maintain sound notification systems. Laws and codes may require such systems or the use of sound notifications may be recommended by an authoritative body. For example, at Japan’s train stations, plans are in place to implement more sounds in addition to the sound that indicates the location of the wickets. The plans include adding sounds to indicate the entrances to restrooms, the locations of stairways that lead to train platforms and the above-ground entrances to subway stations.
Adding sound notifications to existing braille plaques and tactile guide maps are intended to enable visually impaired passengers to move without hesitation and reach their intended destinations in the often congested environments of Japanese train stations. However, for sound notifications to be of value to hearing impaired passengers who want to determine their current locations and the direction of their intended destinations, it is not sufficient that the sound notification be loud enough to hear and clear enough to understand. It is just as essential and important that people hearing the sound can determine the direction and location where the sound originated. Let's take a look at some real-life examples.
<< Examining Two Station Wicket Sound Notification Examples >>
I took Photo A at the wicket of the train station closest to my home. In the lower portion of the photo can be seen the yellow tactile dot floor markers that guide a rider to use the entrance where a station attendant is on duty. A loudspeaker is installed on the wall near the attendant’s booth. I also took Photo B at the wicket of the next station. Here the sound notification loudspeaker was in a location that is already in the interior concourse of the station rather than at the station attendant’s booth. Also, the loudspeaker was installed on the ceiling instead of on the wall. Even though these two stations are part of the same train line, from an acoustical perspective, the loudspeakers are installed in totally different locations at each station.
In both cases, the angles of the loudspeakers prevent the sound notifications from reaching many parts of the area that forms the vicinity of the wicket. It seems to me that it cannot be easy to walk directly to the station attendant’s booth by relying solely on the acoustic guidance of the sound notifications from the loudspeakers.
In practice, visually impaired people I know may not use the entrance staffed by a station attendant. Instead, when they approach the wicket area, they listen for the sound that automated wickets make after each passenger successfully passes through it and, guided by this sound plus the tactile dots on the ground and their individual memories of previous use of the same station, visually impaired persons mostly use the automated wickets.
<< The Situation at a Train Station Platform >>
The most dangerous place at a train station is the station platform. When passengers leave a train, they can feel the tactile dots on the ground and these indicators guide visually impaired passengers to a stairway that goes to the station’s wickets and exit. Some stations have a loudspeaker installed overhead at the stairs to aid visually impaired persons in finding the location of the stairway. The most used sound notification for this purpose sounds like the whistle of a bird.
At the main train stations in Tokyo, during hours when the comings and goings of large numbers of people contribute noise to the environment and multiple trains constantly arrive and depart, and where the sound environment also includes PA system announcements about train service and passengers’ conversations and the general noise of a congested place, a sound resembling the soft whistle of a bird is a difficult sound to hear amidst the competing noises. By contrast, at times such as mid-day when there are no competing PA system announcements and few passengers and trains, it seems easy to hear the sound notification even on subway platforms that have environments with low sound absorption.
The ease of hearing sound notifications at train stations depends on multiple factors, including where and how the loudspeaker is located and the environmental acoustics of the space as well as the time of day, and perhaps other factors I have not identified here. Recently, the Japan Ministry of Land, Infrastructure, Transport and Tourism (MLITT) issued a policy stating that train station attendants should help visually impaired passengers. Considering the multiplicity of hardware implementations and location constraints, the policy focuses instead on the support of personnel on site at the train stations. In my opinion, instead of imposing all of this responsibility on station attendants who are already constantly busy handling other matters, wouldn’t it make good sense to have a campaign to educate the general public to be aware of people around them and encourage everyone to assist visually impaired persons when they see them approaching the train entrances and exits?
Nagata Acoustics Inc.
Hongo Segawa Bldg. 3F, 2-35-10 Hongo
Bunkyo-ku, Tokyo 113-0033, Japan
Tel: +81-3-5800-2671, Fax: +81-3-5800-2672
1990 S. Bundy Drive, Suite 795
Los Angeles, CA 90025
Tel: +1-310-231-7878, Fax: +1-310-231-7816
75, avenue Parmentier
Tel: +33 (0)1 40 21 44 25, Fax: +33 (0)1 40 21 24 00