News 17-04 (No.352)
Issued : April 25, 2017
Pierre Boulez Saal Opens in Berlin
By Daniel Beckmann
Exterior of Boulez Saal ©Volker Kreidler
After a 3-1/2 year construction period and a 1-1/2 year period for design, the Pierre Boulez Saal opened to international acclaim with a gala concert on March 4, 2017.
As we reported in November 2015, Nagata Acoustics was invited by Frank Gehry to design the acoustics for the hall he was designing for his friend Daniel Barenboim. The comparably short gestation time for this project, roughly five years, was enabled by the fact that the project is fundamentally the reuse of an existing building. More than being a renovation of an existing large space, which hints at already being prepared for music, such as the Cremona Chamber Hall (October 2013), this new hall was created by dismantling a substantial portion of the existing internal structure, which was formerly a scenery warehouse for the Berlin State Opera next door.
Having the state opera, the “Staatsoper Unter den Linden” one of the most important opera houses in Germany, next door would hint at the centrality this new venue is expected to occupy in the physical and cultural landscape in Berlin. With an address of Französische Strasse 33D, the hall occupies a prime location in the Mitte (Center) district in Berlin, and together with the Staatsoper serves as an end point to a new sort of musical axis in the city. The other end of the axis is formed by the Berlin Philharmone, with its main hall and the Kammermusiksaal, and along that axis sits the Schauspeilhaus and the Komische Oper.
The hall has been eagerly anticipated in Berlin, as it fulfills a need for a medium-sized performance space in Berlin. This is the first purpose-built hall for chamber music with between 500 to 700 seats in central Berlin. The nearby Kammermusiksaal at the Berlin Philharmonie already has a large capacity of 1,180 seats, and the main hall at the Philharmonie is very large with 2,250. Even in the Schauspeilhaus, less than 400m away, offers 1,600 seats and the next door Staatsoper seats 1,800 persons.
<< Architectural & Acoustical Design >>
Pierre-Boulez-Saal prepared for Piano performance
Glass fins and floating balcony
During the first meeting between Frank Gehry and Daniel Barenboim, alrady the idea for the hall had taken root – Mr. Gehry had drawn the proverbial “napkin sketch” of the oval hall. However, the first design by Gehry took a more conventional approach, with the performers at one end of the room, and the audience facing only them directly. But, soon thereafter, when the design was presented, Barenboim’s response was “Frank, I want the oval, please, please!” The sketched oval now occupies a prominent role in the hall, providing the cover art for the season brochure and the opening week’s program book.
By moving to the oval form with the stage in the center, surrounded by seating on retractable wagons, a version of Boulez’s “Salle modulable” could be achieved. The oval form serves to foster a strong sense of community within the audience, by reducing the distance for all audience to the minimum possible. Loose seats on the stage, placed flexibly for each performance depending on the musicians layout, and comprising up to 100 of the 630 total seats, further enhance the sense of connection within the audience, and also with the musicians. Even in other chamber music halls with smaller stages, this degree of closeness is not often encountered, where one can sit close enough to read every note of music on the stands. Occassionally, in larger concert halls such as the Berlin Philharmonie or Carnegie Hall, chairs are placed on the stage for concerts where the entire stage area is not used by an ensemble.
As shown in the plan and section at right, the seating layout for both the balcony and main floor are oval shaped. The two oval plans are rotated slightly against each other. The balcony appears to float above the audience of the main floor, as it is supported only at the points where it touches the outer walls, and without any columns below. Further enhancing the dynamism of the balcony, the floor of the balcony is not level, rather, it gently rises and falls by one meter in height as the ring is traversed. Acoustically, the balcony is designed to be as minimally intrusive as possible, by using thin pipe railings, and by the innovative overall structure of the balcony: the vertical surfaces of the balcony are all covered by an acoustically transparent mesh, and the concrete structure behind the mesh is more like a truss, with large holes measuring 54cm wide and 107cm tall, allowing sound to pass through and reverberate in the open corner volume behind the balcony. The reverberation time was measured at 1.9 seconds (unoccupied, at 500Hz), an unusually long reverberation time for a room with only 630 seats.
One of the most unique acoustical features of this small hall is the glass “fins” which are suspended from the underside of the balcony. These fins serve a similar purpose as the side balconies in a classical shoebox hall. Many astute readers will probably notice that the hall has a strong concave shape, which is generally not considered acoustically advisable. However in this case, the difficulty is managed by the minimizing of reflective surfaces which are oval in plan, and dividing any remaining convex surfaces into multiple segments which are then made highly diffusive. Between these elements and those described in the previous article of November 2015, the resulting acoustical environment is quite superior, with a unique blend of clarity enabled by the room shape, together with a satisfying reverberance.
<< Opening >>
The opening program of the hall was well chosen to highlight the unique acoustical features of the room, and especially the hall’s namesake Pierre Boulez; two of his compositions served as the opening and closing works on the program. Multiple performance opportunities were presented by the hall, as displayed in the first piece “Initiale” by Pierre Boulez, written for seven brass instruments. The musicians were divided into two groups, and placed on opposite sides of the balcony from one another, and Daniel Barenboim conducted from yet another point on the balcony. Following this brief opening of the hall, the focus returned to the stage center, where first a Schubert song “The Shepard on the Rock” for soprano, clarinet, and piano then a Mozart Piano quartet were performed. Larger pieces which seldom receive live performance also featured prominently on the program, such as Alban Berg’s Chamber Concerto for Violin, Piano and 13 wind instruments, a landmark work of modern music. Finally, the program closed Jörg Widmann’s “Fantasie for Solo Clarinet” also performed from the balcony, and with Boulez’s “sur Incises”, a landmark work of contemporary music scored for three pianos, three harps and three percussionists. This final work on the program successfully highlighted the acoustics of the room, and with its purposeful play with harmonics and overtones, provided an example of work which must be experienced in concert.
77th Acoustics Symposium of the Architectural Institute of Japan: “pu Sensor Probe Applications and Considerations”
By Fumiaki Sakamaki
On February 2, 2017, I attended the 77th Acoustics Symposium of the Architectural Institute of Japan (sponsored by the Institute’s Measuring Methods for Architectural Acoustics Subcommittee). The session focused on a measuring instrument that combines sound pressure (p) and particle velocity (u) sensors in a single device. (In this article I use the term “pu sensor probe” for this device.) In addition to presenting practical field application successes of the probe’s use and pu sensor research, the session also included examples of situations in which the probe’s measurements might be inaccurate, how the technology might contribute to more precise acoustic measurements, possible future applications and the appropriate scope of use for this technology.
<< An Introduction to How pu Sensor Probes Work >>
To briefly introduce readers to the science behind acoustic particle velocity sensors, I will explain that particle velocity is an important, fundamental concept in the discipline of acoustics. Acoustic particle velocity is defined as the speed of a particle as it transmits a sound wave through the medium of air. While this concept may at first seem difficult to grasp, particle velocity is a physical value that is essential in a variety of acoustical measurement situations. For example, when investigating the sound emission characteristics of sound sources, a strict approach considers it insufficient to only measure the sound pressure. The sound intensity (that is, the amount of sound energy transmitted through a specific unit of area in a specific unit of time) must also be measured. Because sound intensity is defined as the product of sound pressure (p) multiplied by particle velocity (u), both of these values must be measured in order to calculate the sound intensity of a sound source’s sound emissions.
Traditionally, there has not been a good way to directly and accurately measure particle velocity. Typically, instead of direct measurement, particle velocity has been calculated as an estimated value by placing 2 microphones side by side and measuring the minute difference between the sound pressures at each microphone. (This is known as the 2-microphone or p-p method.) To address this technological limitation, in 2001 the Dutch company, Microflown Technologies developed a particle velocity sensor probe that more directly measures acoustic particle velocity. Inside the sensor probe are 2 very thin platinum wires placed in a parallel orientation. The probe uses electrical current to heat the wires to a temperature of 2000 C. When air flows across one of the wires, the wire’s temperature decreases. The mechanism of the sensor probe measures the temperature difference between the 2 wires and uses the temperature difference to calculate the particle velocity.
<< Presentations of pu Sensor Probe Field Applications >>
Kajima Corporation’s Mr. Takebayashi and the National Institute for Land and Infrastructure Management’s Mr. Hiramitsu presented current findings on use of the pu sensor probe. For measuring sound energy density and sound isolation performance or floor impact sound levels in interior spaces, the findings indicate that the number of sample points needed when measuring an interior space can be reduced by using the pu sensor probe. The reason is that the probe’s results exhibit less variance among the sample points’ values because particle velocity is included in the measurements.
Haseko Corporation’s Mr. Aida presented a field application of the pu sensor probe that the company uses to detect sound isolation defects that occur during the fabrication process of installing heat insulation and drywall composite panels directly to concrete. By using the pu sensor probe to measure and visualize the particle velocity in the vicinity of a panel, the locations of sound isolation defects by the panel’s resonance phenomenon in the panel material can be determined.
Toda Corporation’s Mr. Koizumi also shared an example of how his company used the pu sensor probe. The company is studying the application inverted phase vibration to window glass to improve the sound isolation characteristic of the glass. The inverted phase vibration uses noise cancellation (also known as “ANC” Active Noise Control) to reduce radiated sound. Mr. Koizumi reported on how Toda Corporation places the pu sensor probe near the glass being tested and measures the particle velocity in connection with testing the vibration characteristic of the glass and ANC noise reduction efficacy.
Mr. Iwase, Professor Emeritus at Niigata University also spoke, presenting both examples from before the pu sensor probe became available and examples of possible uses of the probe. His examples included measuring particle velocity distributions near a perforated panel and using particle velocity to estimate the depth of a crack in concrete. His presentation elucidated how the ability to observe particle velocity can be applied in situations that have special sound field characteristics.
<< Current Calibration Limitations >>
While the presented field application examples demonstrated the pu sensor probe’s promise as a useful tool in various situations, other presenters shared some caveats and other considerations. Professor Otsuru of Oita University and Mr. Sugie of Kobayasi Institute of Physical Research raised the possibility that the probe’s calibration method and calibration timing (that is, the duration between when the probe measurement and the calibration occur) may influence the measurement results in a non-trivial way. This point and other comments led to lively discussion. In addition, because only one vendor manufactures the probe, and because the product requires special handling and is rather difficult to use, the pu sensor probe has not been widely adopted for use. As a result of the probe’s lack of adoption and limited use, the data remains insufficient to fully validate the probe’s accuracy.
Given the possibilities and interest in the pu sensor probe, I hope that research and efforts to develop this technology will continue to be actively pursued.
Exploring Possibilities of Music—Towards an Inclusive and Accepting Society
By Kosuke Suzuki
On February 26, 2017, I attended a “Seminar and Discussion - Exploring Possibilities of Music” event in the Exhibition Hall of Muza Kawasaki Symphony Hall. The organizers schedule these series from time to time throughout the year, focusing on a variety of areas of interest. Topics from the past include fields such as community building with local J. League soccer team, fundraising of orchestras, and development of new digital music instruments. Each event includes a seminar portion followed by discussion open to all attendees. While each of the “Seminar and Discussion” series target specific audiences and have limited seating availability, reservations are open to anyone interested in attending the event.
This year, the topic was “Towards an Inclusive and Accepting Society” and was divided in a 3-part series. The series focused on the topic of barrier-free access and, in particular, on how halls and other venues are adapting to the Japanese “Disabled Persons Discrimination Elimination Act” that went into effect in April, 2016. The series’ primary target audience was managers and other employees of theatres and halls.
The 3 events in the series each consider the needs of a different disabled population. The first event’s topic discussed needs of persons with mobility disabilities, the second—February—session addressed the needs of persons with hearing impairment and the third event held this month was about visual impairment.
The event that I attended included broad areas of discussion: what does hearing impaired mean, what it means to be hearing impaired person in a concert hall or theatre, and, what kind of accommodations do halls and similar venues need. The attendees included not only Muza Kawasaki Symphony Hall employees, but also individuals from other organizations, such as Kanagawa Kenmin Hall, Tokyo Metropolitan Theatre and Owl Spot Theater in Toshima Ward, Tokyo.
The seminar portion included 2 separate lectures. Ms. Masako Hagiwara, Deputy Director of the Japanese nonprofit organization, Theatre Accessibility Network, delivered the first lecture, entitled “What Does It Mean To Be Hearing Impaired?” Ms. Sakura Yamashita of Pioneer Corporation delivered the second lecture, entitled “An Introduction to "Listen Through the Body Concert"".
The event organizers had arranged for sign language translation during the entire event and also used the UD Talk app (described in October, 2016 newsletter) to provide real-time conversion of speech to visually displayed captions so that the event provided an example of inclusion and accessibility for attendees with all levels of hearing impairment, including Ms. Hagiwara, who has total hearing impairment. The arrangements enabled everyone who attended to participate in the discussions and the lectures. Below are my notes and impressions from the lectures and discussion sessions.
<< What Does It Mean To Be Hearing Impaired? >>
FM Hearing Aid System at MUZA Kawasaki
Symphony Hall and their Writing Board
While we may generally use the term “hearing impaired” as a catchall designation, we need to understand the many different conditions included in the term. There are lack of hearing from birth, hearing loss associated with the ageing process, inability to hear high pitched sound or low pitched sound, inability to hear soft sounds, inability to hear sound from right or left, and so on. In this sense, accommodations should be devised not only for performance functionalities but also for receptions as well.
Currently, the hearing aid systems installed in most halls and theatres are either magnetic induction loop systems or infrared/FM hearing assist systems. These systems convert sound to a magnetic field or radio wave, respectively, and a receiver that the hearing impaired person has or rent from the venue adjust to suit their hearing condition. Unfortunately, there are people with very narrow audible range that these systems provide no benefit to. Also, individuals often prefer one or the other of these systems, while venues typically install only one of these systems. If possible, it would be better for venues to offer multiple options from which hearing impaired patrons can choose.
Also, in addition to devices that adjust sound to help the hearing impaired, the adoption of technologies that transform audible information to text and visualized images could be considered. In recent years, the variety and precision of voice recognition devices has increased significantly. Theatres are now adding closed caption displays and, hopefully, concert halls will also install this functionality and proactively use it when concert programs include pre-concert talks and or other spoken-word programming.
Another consideration is how the use of these technologies affect other patrons in the audience. When hearing impaired patrons put on headphones or operate a smartphone like device to connect with a hall’s aiding system, these actions may intrude on the concert experience of other patrons seated nearby, leading to disagreements between audience patrons. Understanding the barrier-free support that a hall provides needs to permeate the consciousness of the general public as well as be understood by the venue’s administrations and employees.
<< An Introduction to "Listen Through the Body Concert" >>
"Listen Through the Body" system
on a normal stacking chair
In 1992, the founder of Pioneer Corporation developed a system he named “Listening through the Body” that can be installed onto an existing chair. This is a seat cushion and pillow-like device with vibrators buried into it, with signal processors transforming the music performance to vibrations that can be felt by the body. The system creates a way for hearing-impaired patrons to feel a music performance through their body.
During her presentation, Ms. Yamashita shared about past "Listen Through the Body Concert". Japan Philharmonic Orchestra had been performing at Suntory Hall, Tokyo Metropolitan Theatre and Yokohama Minato Mirai Hall that had some seats with the “Listen Through the Body" system available. There were other variety of performances introduced, such as original musicals and Hand Signing Chorus.
They reminded me that sound from pipe organ or Japanese Taiko drum often create sensation of vibrations which enhances the experience of hearing for more people. Perhaps a concert hall with a floor structure that lets vibrations on the stage floor reach the audience seats enable a greater diversity of people to enjoy the performances.
The February “Seminar and Discussion” strengthened my passion for continuing to work on creating environments that increase the diversity of people who can experience and enjoy the “Quietness, Comfortable Sound, and Excellent Acoustics” we always aim to achieve.
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