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Psychoacoustics
Applied Acoustics 34 (1991) 293-296
Book Reviews
Psychoacoustics. By E. Zwicker and H. Fastl. Springer-Verlag, Berlin, FRG, 354 pp. ISBN 3 540 52600 5. This book is a seminal work of psychoacoustics. It is quite a new effort and not, as someone might assume from the similarity of the title, only the latest translation of Zwicker's German book Psychoakustik, which appeared in 1982. It summarises exclusively the results of the research groups concerned with hearing phenomena, and led by Eberhard Zwicker, from the very first beginning in 1952 in Stuttgart up to the recent past at the Institute of Electroacoustics in Munich (since 1967). The book gives evidence of the tremendous amount of scientific work that has been performed by the Institute's psychoacoustic staff. This is also documented by the 30 pages of literature issued by the Zwicker School at the end of the book. An important aspect for the interested English-speaking reader is the fact that here the content of many papers originally written in German is made available in English for the first time. The book now has particular significance since Eberhard Zwicker died soon after its appearance. It turns out to contain the quintessence of the whole of an extremely fruitful scientific life. The co-author, Hugo Fastl, is one of the most prominent members of the Zwicker School and many essential parts of the scientific research can be attributed to his activities in the group. Both authors are engineers, regarding the ear as an information receiver, the properties of which are investigated with a well-refined arsenal of specialised acoustic signals, revealing the ear-related manner of acoustical information processing. With the resulting functional models, based upon the results, the essential (peripheral) processing is described in detail. It is not possible to summarise the book's content adequately in a few words. The large amount of detailed research results included makes this a real handbook of psychoacoustics. It contains the most comprehensive collection of psychoacoustic facts and models that I know. It comprises 16 chapters, the first three of which give a general introduction into the sounds and methods used. As part of the background material on peripheral 293 Applied Acoustics 34 (1991)----~ 1991 Elsevier Science Publishers Ltd, England. Printed in Great Britain
294
Book reviews
processing they describe the important kinds of otoacoustic emissions. These reveal the active and non-linear behaviour of the cochlea described by a powerful non-linear feedback model. Throughout the text the psychoacoustical facts and the data produced by the models are united to give an integrated picture and the deeper understanding that the authors quite rightly expect. The next and biggest part of the book contains the psychoacoustic results (and models) concerning the frequency and temporal resolution of the ear on masking, pitch and pitch strength, critical bands and excitation, and just noticeable sound changes. This underlines the book's comprehensiveness. For example, when reading Chapter 4 you find nearly everything you might want to know about monaural masking, how different masking signals mask different test sounds, simultaneously or non-simultaneously, in the spectral or in the time domain, including both the masking period pattern and the pulsation threshold together with masking models. The wish to measure subjective acoustically evoked sensations as if they were physical entities has led consequently to the development of psychoacoustic measures including sharpness, sensory pleasantness, fluctuation strength, roughness and subjective duration. The most elaborated measure in this context is the loudness, which is fully described in its spectral and temporal aspects. The whole set of the so-called ear-related parameters is included in the third part of the book. After a look at the non-linear distortion properties of the ear and of some binaural hearing aspects the fourth part of the book ends with a chapter on the applications where the importance of the research in the fields of noise abatement and audiology is particularly stressed. Actually, the field of applications will extend in the near future and this book will be a basis for the development of more sophisticated descriptions of complex sound sensations. This is already shown by the examples of sensory pleasantness and unbiased annoyance. According to the engineering approach which lies behind the book, the models reproduce the psychoacoustic results which are obtained when a laboratory subject listens to a sound attentively. This fundamental assumption has to be taken into account when one wants to apply these results and models in real life, where a variety of additional influences become an important part of the global effects of sounds. This book is aimed at research scientists, development engineers and research students in the fields of psychoacoustics, audiology, auditory physiology, biophysics, audio-engineering, musical acoustics, noise control, acoustical engineering, ENT medicine, communication and speech science. In my opinion, it is not an easy book to read for a novice student in any of these fields, because the information content is highly concentrated. But for
Book reviews
295
advanced students, researchers and experts it is an essential source of psychoacoustic knowledge. I expect this book to become a sine qua non for such people whether I recommend it or not. But I do recommend it.
Reinhard Weber
Underwater Electroacoustic Transducers. By D. Stansfield. Bath University Press, Bath, UK. ISBN: 0861970829; 1873082096. A new book on underwater acoustics is a rarity and one which brings together much of the work performed on underwater acoustic transducers since the Second World War is exceptional. Dennis Stansfield's book has filled a much-needed gap in the current literature. It is not that the information provided has been unavailable, in fact there is little in the book which is entirely new. However, the book does combine the best of a large number of papers and books written over the past 30 years, a fact which can easily be verified by studying the extensive lists of references at the end of each chapter. The book focuses on transducer design, particularly those based on pistons, and does not attempt to cover the associated fields of transmitters, amplifiers and filters. As such it is not a replacement for existing standard texts, rather a very useful addition. The first two chapters cover all the basic concepts necessary for a thorough understanding of transducers and would make a good foundation for an introductory course in this field. Dennis Stansfield then expands these topics through the conventional mathematics to a point where they can be applied to practical transducers. The book then addresses the following issues:
Materials, both electrostatic and magnetostrictive. This section also includes three very useful tables of physical properties for the active elements and construction materials. Equivalent circuits, including a very clear description of the analogy between mechanical and electrical equivalents, admittance loops, the maths of equivalent circuits and efficiency. Bandwidth, transducer matching and the way in which a transducer naturally acts as a filter. Acoustic radiation, first from a single element and then by considering how multiple elements can be made to radiate with a known phase relationship. Directivity patterns are also discussed with brief reference to parametric arrays.
Book Reviews
Psychoacoustics. By E. Zwicker and H. Fastl. Springer-Verlag, Berlin, FRG, 354 pp. ISBN 3 540 52600 5. This book is a seminal work of psychoacoustics. It is quite a new effort and not, as someone might assume from the similarity of the title, only the latest translation of Zwicker's German book Psychoakustik, which appeared in 1982. It summarises exclusively the results of the research groups concerned with hearing phenomena, and led by Eberhard Zwicker, from the very first beginning in 1952 in Stuttgart up to the recent past at the Institute of Electroacoustics in Munich (since 1967). The book gives evidence of the tremendous amount of scientific work that has been performed by the Institute's psychoacoustic staff. This is also documented by the 30 pages of literature issued by the Zwicker School at the end of the book. An important aspect for the interested English-speaking reader is the fact that here the content of many papers originally written in German is made available in English for the first time. The book now has particular significance since Eberhard Zwicker died soon after its appearance. It turns out to contain the quintessence of the whole of an extremely fruitful scientific life. The co-author, Hugo Fastl, is one of the most prominent members of the Zwicker School and many essential parts of the scientific research can be attributed to his activities in the group. Both authors are engineers, regarding the ear as an information receiver, the properties of which are investigated with a well-refined arsenal of specialised acoustic signals, revealing the ear-related manner of acoustical information processing. With the resulting functional models, based upon the results, the essential (peripheral) processing is described in detail. It is not possible to summarise the book's content adequately in a few words. The large amount of detailed research results included makes this a real handbook of psychoacoustics. It contains the most comprehensive collection of psychoacoustic facts and models that I know. It comprises 16 chapters, the first three of which give a general introduction into the sounds and methods used. As part of the background material on peripheral 293 Applied Acoustics 34 (1991)----~ 1991 Elsevier Science Publishers Ltd, England. Printed in Great Britain
294
Book reviews
processing they describe the important kinds of otoacoustic emissions. These reveal the active and non-linear behaviour of the cochlea described by a powerful non-linear feedback model. Throughout the text the psychoacoustical facts and the data produced by the models are united to give an integrated picture and the deeper understanding that the authors quite rightly expect. The next and biggest part of the book contains the psychoacoustic results (and models) concerning the frequency and temporal resolution of the ear on masking, pitch and pitch strength, critical bands and excitation, and just noticeable sound changes. This underlines the book's comprehensiveness. For example, when reading Chapter 4 you find nearly everything you might want to know about monaural masking, how different masking signals mask different test sounds, simultaneously or non-simultaneously, in the spectral or in the time domain, including both the masking period pattern and the pulsation threshold together with masking models. The wish to measure subjective acoustically evoked sensations as if they were physical entities has led consequently to the development of psychoacoustic measures including sharpness, sensory pleasantness, fluctuation strength, roughness and subjective duration. The most elaborated measure in this context is the loudness, which is fully described in its spectral and temporal aspects. The whole set of the so-called ear-related parameters is included in the third part of the book. After a look at the non-linear distortion properties of the ear and of some binaural hearing aspects the fourth part of the book ends with a chapter on the applications where the importance of the research in the fields of noise abatement and audiology is particularly stressed. Actually, the field of applications will extend in the near future and this book will be a basis for the development of more sophisticated descriptions of complex sound sensations. This is already shown by the examples of sensory pleasantness and unbiased annoyance. According to the engineering approach which lies behind the book, the models reproduce the psychoacoustic results which are obtained when a laboratory subject listens to a sound attentively. This fundamental assumption has to be taken into account when one wants to apply these results and models in real life, where a variety of additional influences become an important part of the global effects of sounds. This book is aimed at research scientists, development engineers and research students in the fields of psychoacoustics, audiology, auditory physiology, biophysics, audio-engineering, musical acoustics, noise control, acoustical engineering, ENT medicine, communication and speech science. In my opinion, it is not an easy book to read for a novice student in any of these fields, because the information content is highly concentrated. But for
Book reviews
295
advanced students, researchers and experts it is an essential source of psychoacoustic knowledge. I expect this book to become a sine qua non for such people whether I recommend it or not. But I do recommend it.
Reinhard Weber
Underwater Electroacoustic Transducers. By D. Stansfield. Bath University Press, Bath, UK. ISBN: 0861970829; 1873082096. A new book on underwater acoustics is a rarity and one which brings together much of the work performed on underwater acoustic transducers since the Second World War is exceptional. Dennis Stansfield's book has filled a much-needed gap in the current literature. It is not that the information provided has been unavailable, in fact there is little in the book which is entirely new. However, the book does combine the best of a large number of papers and books written over the past 30 years, a fact which can easily be verified by studying the extensive lists of references at the end of each chapter. The book focuses on transducer design, particularly those based on pistons, and does not attempt to cover the associated fields of transmitters, amplifiers and filters. As such it is not a replacement for existing standard texts, rather a very useful addition. The first two chapters cover all the basic concepts necessary for a thorough understanding of transducers and would make a good foundation for an introductory course in this field. Dennis Stansfield then expands these topics through the conventional mathematics to a point where they can be applied to practical transducers. The book then addresses the following issues:
Materials, both electrostatic and magnetostrictive. This section also includes three very useful tables of physical properties for the active elements and construction materials. Equivalent circuits, including a very clear description of the analogy between mechanical and electrical equivalents, admittance loops, the maths of equivalent circuits and efficiency. Bandwidth, transducer matching and the way in which a transducer naturally acts as a filter. Acoustic radiation, first from a single element and then by considering how multiple elements can be made to radiate with a known phase relationship. Directivity patterns are also discussed with brief reference to parametric arrays.