Recent
Trends
in
Hearing Research
Festschrift
for Seiichiro Namba
Edited
by
Hugo Fastl
Sonoko Kuwano
August Schick
PREFACE
This Festschrift is to honor Professor
Seiichiro Namba on the occasion of his retirement from
Professor Namba's major field is Psychoacoustics. When he was a young boy, he was interested in playing the piano and in making radios, amplifiers and tape recorders. These hobbies led him to study psychoacoustics. His research interests range widely from the basic mechanism of hearing to applied research into the psychological evaluation of musical performance, sound quality and noise. It is noteworthy that he started the study of non-steady state sounds in the 1960's. The importance of this topic can easily be understood when we consider that most information conveyed by sounds depends on temporal variation. He has developed systems to produce non-steady state sounds and conducted a series of experiments on the subjective evaluation of these stimuli. He has maintained since 1968 that the loudness of non-steady state sounds can be approximated by the mean energy level (the equivalent continuous A-weighted sound pressure level: LAeq), and was given the Sato Prize for the study of the validity of LAeq from the Acoustical Society of Japan in 1983.
Professor Namba has also shown that the temporal structure of sounds has a systematic effect on loudness, and has proposed a non-linear model of the dynamic characteristics of hearing on the basis of experiments using sounds with systematic changes in temporal structure. This model can be widely applied: to the perception of piano sounds or the evaluation of machinery noise.
Another of Professor Namba's interests is timbre. He made clear in his doctoral thesis that the complicated impression of timbre can be represented three-dimensionally. He widened the study of timbre to machinery noise and correlated the subjective impression of the timbre of machinery noises to their physical values. This study provides a psychoacoustic basis for the control of machinery noise. The present book contains several studies of the timbre of noise.
The
measurement of instantaneous impressions of fluctuating sounds along the
temporal steam has occupied him and he has developed new methods for this,
called "the method of continuous judgment by category" and "the
method of continuous judgment by selected description". Using these methods, the relation
between overall judgments and instantaneous judgments, the factors determining overall
and instantaneous judgments, trade-off effects between sound sources, and other
aspects have been examined. The
results give important information concerning the hearing mechanism and are
relevant to noise control engineering.
The methods Professor Namba originated are widely used in European
countries and
Professor Namba is a widely acclaimed figure, well known for his cooperation internationally. In the field of cross-cultural studies, he has been the partner of many colleagues working in Psychology, Physics and Engineering round the world for many years. He was instrumental in reinvigorating comparative Psychoacoustics and his ideas became known in many parts of the world with the result that we now have at our disposal a wealth of cross-cultural knowledge about neighbourhood noise, the assessment of danger signals and attitudes to noise sources of various kinds.
Over
the course of many years Professor Namba has become an important coordinator
and intermediary in establishing contacts between Japanese and foreign research
groups, in particular in the fields of psychoacoustics and noise research. He has looked after and advised many
colleagues on their visits to
Professor Namba has concentrated on research into psychoacoustics and may be regarded as one of the leading pioneers in this field. As can be seen from the impressive list of positions he holds, Professor Namba is in great demand for the coordinating of university research, both at national and international levels.
In the area of the subjective evaluation of noise immissions, he has been involved in the development of procedures for the assessment of road traffic noise and railway noise which already form the basis of political decisions.
Professor
Namba's concern with the problem of meaning based on
semantic differential has led to significant scientific results. He continues to be fascinated by the
concept of semantic differential, applying this technique in all kinds of
fields, particularly in recent years to the investigation of timbre. The results obtained were summarized in
a monograph which has become a standard work in research into applied
psychoacoustics. Today, Professor Namba's methods are used throughout
Professor
Namba has through his studies made a substantial contribution to society and
social welfare. He has been a
member of many committees on noise problems in central or local governments,
such as the Central Commission on Environmental Problems of the Environmental
Agency of Japan, the Environmental Dispute Coordination Commission (Prime
Minister's Office), the Environmental Council of the Environmental Agency of
Japan, the Ministry of Transportation of
Professor Namba is highly esteemed internationally as well as nationally. He is now a member of the International Union of Pure and Applied Physics. He was the President of the Acoustical Society of Japan and is the President of the Japanese Society of Music Perception and Cognition. Also he has been a director of the Acoustical Society of Japan and INCE/Japan. He is a member of the editorial advisory board of Acustica and the editorial board of Applied Acoustics. He gave plenary lectures at the International Congress on Acoustics (1992), the International Congress on Noise as a Public Health Problem (1993) and the International Congress on Noise Control Engineering (1994).
As well as having wide knowledge and expertise in his field, Professor Namba has great enthusiasm for the study of psychoacoustics and is always keenly interested in new approaches and developments. We celebrate him for his achievements in the past and look forward to those in the future.
ACKNOWLEDGEMENTS
The editors are grateful to Professor Tohru Kato of
Hugo
Fastl
Sonoko
Kuwano
August
Schick
BIS Verlag, Oldenburg, Germany, 1996