Acoust. Sci. & Tech. 26, 2 (2005) PAPER Cognitive modeling of musician s perception in concert halls Kanako Ueno and Hideki Tachibana y 1 Institute of Industrial Science, University of Tokyo, Komaba 4 6 1, Meguro-ku, Tokyo, 153 8505 Japan 2 Chiba Institute of Technology, Tsudanuma 2 17 1, Narashino, 275 0016 Japan ( Received 8 July 2004, Accepted for publication 27 October 2004 ) Abstract: In order to investigate the effect of a hall response on music players, we have made various experimental studies up to now. In order to develop this research, one of the most important subjects is to understand the musicians perception of the acoustic effects of halls. Musicians generally perceive the acoustic properties of a concert hall by keeping their performing and by adjusting their playing technique subconsciously. This kind of interactive relationship between musicians and acoustic environment is really important when considering the acoustic values of concert halls for musicians. In this study, musicians awareness of concert halls was investigated through interview survey and the cognitive psychological phenomena of musicians were interpreted by applying the tacit knowing theory. Then the process to extract the musicians perception in experimental studies on concert hall acoustics is discussed. Keywords: Stage acoustics, Psychological modeling, Musicians perception, Tacit knowing PACS number: 43.55.Hy, 43.75.Cd [DOI: 10.1250/ast.26.156] 1. INTRODUCTION In concert hall acoustics, what music players on the stage require should be considered as well as those for the audience. On this subject of stage acoustics, we have been making experimental studies by having the cooperation of professional musicians. In these studies, it is very important to understand the musicians cognition of concert halls. In most studies on psycho-acoustics, the experiment procedures are based on stimulus-response model. In this case, the subject of the experiment usually just listens to the sound stimuli passively and interactive relationship between human and environment is not assumed. However, musicians perception of concert hall is inevitably related to their performing and active behavior of musician cannot be ignored. Therefore it is necessary to reconsider the psychological model for this kind of study. In this study, the musicians and their cognition in concert halls are firstly investigated by interview survey. Then, the cognitive model for musicians perception of concert hall is investigated by introducing the tacit knowing theory proposed by Michel Polanyi [1,2], which is a theory to explain the system that human recognizes the e-mail: ueno@iis.u-tokyo.ac.jp y e-mail: tachibana@acoust.cs.it-chiba.ac.jp surroundings not only by sensing but also by physical. The results of the interview survey and a simple cognitive model using the concept of tacit knowing have been introduced in our previous paper [3]. In this paper, they are again presented and further deepened consideration and discussion are made. That is, the cognitive system to form a musician s perception by his/her tacit knowing are explained and modeled as a complex mechanism. Based on the model, the method of subjective experiment to investigate musicians perception of concert hall acoustics is considered and discussed. 2. INTERVIEW SURVEY 2.1. Procedure In order to investigate the relationship between musicians and concert halls, interview survey on professional musicians was conducted while the laboratory experiments using a simulated sound field were conducted [3]. That is, each musician was requested to visit our acoustic laboratory and to cooperate in the study of stage acoustics. Then, they participated in the subjective experiment to investigate the relationship between subjective judgment and acoustic properties and they were also interviewed. The interview was conducted by asking the questions as shown in Table 1 and each musician answered the 156
K. UENO and H. TACHIBANA: MUSICIAN S COGNITION Table 1 Questions to musicians in the interview survey. Topics Experience Awareness in concert Awareness in halls Communication about the halls Examples of the question Career, Daily activities (Frequency of concert, Performance style, etc.) Experience in concert halls (The number and the type of the halls which he/she usually use) What do you aim at and what are you aware of in concerts? How do you percieve concert hall in the performance? Does the awareness change according to the performance style, music piece, or one s position in a concert? Do you adjust your performing technique according to acoustics of a hall? How? What are the characteristics of favorable/unfavorable halls? Has your awareness of concert hall and adjustment to halls changed in your experience? How? Do you think that musicians have the same feelings to the halls? With whom and in what situation do you talk about concert halls? How do you express the acoustic characteristics of concert halls? questions through conversation with the interviewer. Thirteen professional musicians (four violinists, three violists, three flutists, one clarinet player, and two oboists) participated in the interview survey. 2.2. Results As a result of interview survey, a variety of comments with the own expression of each musician were obtained. Typical answers are presented below. Awareness of concert halls. To the question about musicians awareness of concert halls, the following answers were obtained.. The musical instrument is not a tool but a part of my body. I aim to play the musical instrument so that I am united with the concert hall as one. When I succeed in this unity, the concert hall is in my heart. (Vn.-A). A concert hall is the extension of my musical instrument. I always focus my mind on the audience area and feel how my performance sounds there. (Ob.-A). The performance with and without consciousness of a hall is completely different. In a hall, by uniting the reverberation of the hall and my sound and by filling the hall with my sound, I can play the hall in the same manner as I play the musical instrument. (Ob.-B) In these comments, it is indicated that musicians usually express their music using not only their musical instruments but also the hall. Therefore, they have to manipulate the hall as well as their musical instruments. It means that they extend their physical sensation not only into the musical instrument but also into the hall. Adjustment of performance. As mentioned above, musicians are much aware of concert hall in their performance. Then, how does the concert hall acoustics influence the performance? Musicians answers were;. When I stand on the stage, I grasp the rough characteristics of the hall during tuning. Next, I try to match my playing to the hall by changing the speed and movement of bowing, tempo of vibrato and pressure of fingers while I listen to the sound of the hall by changing the direction of the instrument or standing position. In order to send my image of musical nuance to the audience, I change the performing technique to cover the defect of the hall when the hall has peculiarities. (Vn.-A). I play the instrument to match the sound to the hall by listening to the length of reverberation, timing of the hall response and tonal quality of harmonics. For example, when the hall sound is hard, I cut the high frequency of harmonics by making more area of my lips touch the reed and making the vibrations soft. When the hall has peculiar characteristics on a certain sound, I have to adjust each tone. (Ob.-A) In these comments, it is shown that they make adjustments in order to match their performance to the room acoustics. In this, the acoustic characteristics of the concert hall are perceived precisely because they are the essential information to make such adjustment. Here, it should be noted that the adjustment is peculiar to each musician because it is conducted by his/her own intention based on his/her experience, and therefore, the perceived characteristics of a concert hall can be different among musicians. Most musicians commented that they had acquired the technique to make such adjustment through their several years experience of performing in concert halls. Physical. To the question about how they make the adjustment to the concert halls, the following answers were obtained.. In concert halls, I sense the reverberation and adjust the playing technique as a reflex to search for the best performance in the hall. So, I am conscious of how I should play, not how the acoustics of the hall is. (Vn.-A). I make adjustment of performance almost subcon- 157
Acoust. Sci. & Tech. 26, 2 (2005) sciously, as a kind of physical response. If it does not work as I imagine, then I would think what I should do logically. (Ob.-A). Before the concert, I often talk about the concert hall with my colleagues to get information of the hall. It is necessary to make preparation before going to the hall and I make reeds to suit the hall in advance. When I get to the concert hall and begin to play in it, I make various adjustments without thinking. (Ob.-B) In these comments, it is indicated that they are not conscious of acoustics of concert halls but conscious of how they should do in the circumstance. It is also mentioned that the adjustment in concert hall is usually conducted by physical response without logical thinking. Communication among musicians. The next question is how the musicians communicate among themselves on the acoustics of a concert hall. Their answers were;. During rehearsal, co-players and I talk about the playing technique suited for the hall. (Vn.-A). In quartet, we often talk about the way to play or tempo of music because we change them according to the reverberation of the hall. In orchestra, we usually communicate through performance. We talk in words only when we have serious problems. (Va.-A). In orchestra, we can find out each other what each player feels by the performance or breathing without talking. When we feel that the same feeling is naturally shared, we do not talk any more. When it is difficult to make consensus naturally, we talk in words logically to solve the problem. (Ob.-A) In daily performance, musicians conversation concerning concert halls is mainly for the purpose to align the playing technique to create good ensemble. Therefore, it can be said that the words to express the characteristics of a concert hall are not necessarily used in their daily conversation. Here, it should be noted that knowing is different from telling. For example, musicians cannot necessarily express their perception of acoustics of a concert hall by words even if they have clear perception. 3. COGNITIVE MODELING Tacit knowing theory. In order to interpret the cognitive process of musicians mentioned above, the theory of tacit knowing is introduced here. In this theory, it is assumed that the perceived particulars are integrated to a comprehensive entity by the function of tacit knowing. Here, the word particulars means fral information to produce a certain physical or conceptual, which is called comprehensive entity in the theory. In the concept of particulars, it is assumed that the information in the brain is not static but being accumulated by human activities at every moment. Thus, the theory explains how a human acquires a skill. In the process to acquire the skill using a tool, a human repeats making an with the tool and sensing its re from the object. By repeating the task, he/she gradually comes to know the meaning of the re and the way to adjust the to achieve the aim and finally, he/she becomes able to use the tool with perfect control as if it is a part of his/her body. That is, he/she acquires the skill. In the skill, he/she extends his/her physical sensation to the object in the relationship between the and the re and perceives the characteristics of the object in detail. However, he/she cannot necessarily tell how he/she acquired the skill and what he/she perceives about the object. This is the process of the tacit knowing. Modeling of musician s performing. Musician s in a concert hall can be explained using the concepts of tacit knowing. When playing his/ her musical instrument, the musician exchanges s and res with the instrument. If he/she has already acquired the skill to play the instrument, he/she can play it with perfect control as if the instrument is a part of his/her body. In other words, a musician can extend his/her physical sensation into the musical instrument. In a concert hall, the musician who intends to share the musical image with audience extends his/her physical sensation into the sound field of the concert hall. Here, he/ she senses the acoustics in the relationship between his/her adjustment of playing technique and the feedback from the concert hall. The characteristics of the concert hall are sensed in detail in this process and reflected in the performing. To use the terms of tacit knowing theory, the characteristics of the concert hall correspond to particulars and they are to be integrated to the performance that corresponds to comprehensive entity. Figure 1 shows the musician s perception of a concert hall in comparison with listener s perception. In the latter case, it can be said that a listener listens to the sound passively and the main function to perceive the sound is only his/her hearing system. On the other hand, in the case Listner Hearing system Sound sound (a) Listeners Fig. 1 Physical Musician Tacit knowing Vibration Music instrument (b) Musicians Performing Hall response sound Sound field in concert hall re Modeling of the performing of musician. Extension of physical sensation 158
K. UENO and H. TACHIBANA: MUSICIAN S COGNITION of the musician, he/she uses his/her physical movement actively in the performance and senses the sound field in the relationship between his/her and the re from the sound field. That is, the musician perceives the sound field through the inter between him/her and the sound field. Thus, the performing that reflects the characteristics of the hall is achieved subconsciously by his/her tacit knowing. Modeling of musician s tacit knowing. The musician s tacit knowing is acquired individually through the accumulation of his/her efforts for years. That is, such musician s background as his/her skill, motivation and careers constitute his/her tacit knowing and form his/her intension in the performance and his/her musical image. In addition, such situation in a concert as music pieces, performance style and his/her role in the performance regulate the intension and the musical image. With the intension and musical image determined by the factors mentioned above, he/she manipulates his/her musical instrument. Figure 2 shows the model to explain these factors and musician s perception in more detail. As shown in this figure, the particulars are related one another complexly and produce performing as an integrated result. The musician s requirements for acoustics are determined by these particulars and his/her perception of the concert hall emerges from his/her requirements. 4. MODELING OF SUBJECTIVE EXPERIMENT BY ACOUSTICIAN In order to investigate the effect of acoustic phenomena on human, subjective experiments are often conducted. When the model of musicians is assumed as is mentioned above, the experimental field and procedures should be also reconsidered. Situation in a concert Music piece Performance style Role in the performance Place, Audience etc. Fig. 2 Performing sound Musician "particulars" Musician's background Skill, Motivation, Careers, Taste, Experience, Performance style, Characteristics of the instrument Intention in performance Musical image Requirement for the hall physical dimention Physical Perception of the hall Concert hall Sensation Hall response Tacit knowing in musician s performance. Concerning the experimental setup for musicians, test sound, in the preliminary preparation, cannot be the same as in the common cases of psycho-acoustic experiment modeled in Fig. 1(a). For the musicians, it is necessary to construct the sound simulation system that can generate the hall response following the performing sound as if the subject is on the stage of a concert hall. We have developed a sound field simulation system in which 3-dimmentional sound field is produced using 6- channel real time convolution system and loudspeakers set in an anechoic room as shown in Fig. 3 [4]. In the system, the sound of a musical instrument played by the subject (dry music signal) is picked up through a directional microphone and convolved with the directional impulse responses measured on the stage of a real concert hall in six orthogonal directions. Using this system and referring the data of acoustic condition on various stages, experimental conditions are prepared. Directional Mic. (Sony C48) (for 6 directions) 300mm 300mm Omni-directional Loudspeaker (TS-12M) 2,000mm Directional Mic. (Sony C48) Mic.Amp Equalizer for a directional mic. Equalizer for a measurement system Real Time Convolver (Lake Huron 3.0, 6ch.) 1200mm Audience Area Equalizer for loudspeakers (6ch.) Power Amp (6ch.) (a) Measurement on stages Fig. 3 Loudspeakers (b) Sound field simulation in an anechoic room Outline of the 6-channel sound field simulation system. 159
Acoust. Sci. & Tech. 26, 2 (2005) Situation Music piece Performance style Role in the performance Place, Audience etc. Subject (Musician) "particulars" Musician's background Skill, Motivation, Careers, Taste, Experience, Performance style, Characteristics of the instrument Intention in performance Musical image Requirements for the hall physical dimention Physical Perception of the hall Sensation Understanding Instruction Understanding Understanding Question Answer Experimenter (Acoustician) "particulars" Architectural Backgrounds features of halls of the musician Intentions and requirements of the musician Musician's expressions Musician's judgments Variation of acoustic condition on stages conceptual dimention Musician's Acoustic perception properties Performing sound Hall sound Control Experimental condition (Simulated sound field) Measurement Fig. 4 Model of the subjective experiment on stage acoustics. In the subjective experiment using the system mentioned above, the cognitive system of the experimenter (acoustician) has to be modeled as a complex mechanism as well as that of the subject (musician). By applying the model shown in Fig. 2, the subjective experiment on stage acoustics being performed by the authors can be modeled as a diagram shown in Fig. 4. First, in the experiment, it is necessary for the subject (musician) to sense the characteristics of the test sound fields by performing as he/she does in his/her usual activities. Second, the musician s perception should be extracted by the experimenter (acoustician). Here, the following two points should be noted; one is that the requirements for the acoustics are different among musicians and also among performing situations and the other is that the meaning of a word to express their perception of the hall is not necessarily common for all musicians. For the former point, the situation of the experiment should be carefully planned/determined and explained to the musician by way of instruction by which the subject fixes the image of the performance. The subject s background cannot be controlled in the experiment and therefore, we have to understand his/her background as well as his/her requirements for the performance determined by his/her intension and musical image. For the latter point, the method to extract musicians perception of the hall should be developed. In our experiment, we ask the musician about his/her perception through corporative conversation to promote his/her verbal expression and to understand the musician s perception as well as his/her other particulars. As another trial, we measure the musician s perception by applying individual scales which are set for each musician based on the preliminary investigation on the requirements and expressions of each musician [5]. If common scales are used for every musician, it is necessary to assure that each scale has the common meaning among musicians. In the analysis of the experimental results in this kind of study, the usual statistical examination to verify the relationship between psychological responses and acoustic quantities is not necessarily effective. Musicians judgment of the acoustic conditions is influenced by their particulars as mentioned before, and therefore it is necessary to interpret the fluctuation and difference of judgments by understanding the musicians particulars. In the process, the corporative conversation between the subject and the experimenter is essential. Therefore, we always execute the experiment with direct communication with the subject (see Fig. 5). Based on these considerations, we have conducted several experimental studies with professional musicians [4 7]. In the results, it has been indicated that the musicians preference or evaluation of acoustic condition are different among them and the judgments on acoustics Fig. 5 Subjective experiment on a musician. 160
K. UENO and H. TACHIBANA: MUSICIAN S COGNITION can vary by the difference of situations (e.g. solo, in quartet and in orchestra). In addition, they do not always use the same word to express a perception. However, when considering the semantic aspects of words to express, the common meaning can be read to some extent and it might be possible to find the relationship between musicians perception and physical acoustic properties. Furthermore, when the judgments and expressions are examined by considering their background and intentions, the difference of the judgments can be interpreted. 5. CONCLUDING REMARKS In psycho-acoustic researches, the common sensation of human is usually the focus and psychological method to measure and extract the common sensation is applied. However, the meaning of acoustic environment perceived in daily activities is not common for all people. Especially, when discussing the sensation perceived through the skill which is acquired by personal experience for years, it should be noted that the sensation is peculiar to individuals. Musicians psycho-acoustics is a typical example. Thus, it is very important to conduct the study of stage acoustics based on the complex psychological model as indicated in this paper. ACKNOWLEDGEMENT The authors wish to thank the musicians who joined in this study for their willing cooperation. This research was partially supported by Grant-in-Aid for Scientific Research (No. 15760435) from the Ministry of Education, Culture, Sports, Science and Technology, Japan. REFERENCES [1] M. Polanyi, Personal Knowledge (The University of Chicago Press, Chicago, 1958). [2] M. Polanyi, The Tacit Dimension (Peter Smith Pub., Gloucester, 1983). [3] K. Ueno and H. Tachibana Musicians perception in concert halls: Experimental study by linguistic structure analysis, J. Acoust. Soc. Jpn. (J), 59, 519 29 (2003). [4] K. Ueno and H. Tachibana Experimental study on the evaluation of stage acoustics by musicians using a 6-channel simulation system, Acoust. Sci. & Tech., 24, 130 38 (2003). [5] K. Ueno, H. Tachibana and T. Kojima, Analysis of musicians evaluation of acoustics in concert halls based on the individualscale method, J. Acoust. Soc. Jpn. (J), 59, 591 602 (2003). [6] K. Ueno, M. Rokutanda and H. Tachibana, Experimental study of stage acoustics for ensemble performance, Proc. WESPAC 8 (2003). [7] K. Ueno, H. Tachibana and T. Kanamori, Experimental study on stage acoustics for ensemble performance in orchestra, Proc. ICA2004, pp. 1893 1896 (2004). Kanako Ueno was graduated from Faculty of Engineering, Tokyo University in 1995, and received Engineering Doctor from Tokyo University in 2003. Research associate of the Applied Acoustic Engineering Laboratory, Institute of Industrial Science, Tokyo University since 1998. Visiting scholar of Boston University, 2004 2005; Awaya award from ASJ, 2000; Incentive Award from The Japanese Society for AI, 2003. Member of ASJ, Architectural Institute of Japan, JSAI, and Behaviormetric Society of Japan. Hideki Tachibana was graduated from Faculty of Engineering, Tokyo University in 1967, and received Engineering Doctor from Tokyo University in 1973. Professor of Department of Computer Science, Chiba Institute of Technology. President, ASJ, 1995 1997; Chief in Editor, ASJ, 1999 2003; President, INCE/Japan, 2002 2004; President, International-INCE 2004 ; Fellow, ASA, 1996 ; Prize of the Architectural Institute of Japan, 1990; Prize of ASJ, 1991; Lord Rayleigh Medal (IOA), 2002. 161