source file: mills2.txt Date: Thu, 19 Oct 1995 09:37:24 -0700 From: "John H. Chalmers" From: mclaren Subject: Tuning & psychoacoustics - post 24 of 25 --- Juan Roederer is one of the more influential psychoacoustic researchers. Like many others in the field, he is biased toward a particular model of the ear.Roederer is strongly biased toward the periodicity theory of hearing. In "Introduction to Physics and Psychophysics of Music," the section on the physical makeup of the ear/brain system shows this bias clearly. In this section there is a great deal of discussion of neurons and neural firing pattern, none at all on the processing of medullar and higher brain areas nor any detailed discussion of von Bekesy's experiments, the physical action of the organ of Corti, etc. However to his credit Roederer does cite extensively the results of Ward, Corso, Terhardt, Sundberg and Lindqvist for the universal preference of stretched invtervals. Thus Roederer, like Helmholtz, is a contradictory figure--deliberately overemphaszing some of the evidence, while remaining open-minded about other contradictory results. Fetis (1943), Ellis (1885) Corso (1954), Ward (1970), Burns (1970), Hood (1975) and Erickson (1983) are all strongly biased toward the ear-as-controlled-by-learned-preference model of hearing. Terhardt and Ward/Burns tend to bury evidence which does not favor their view by dumping a superflux of additional results on top of the relevant data; this has the same effect as squirelling the relevant data away in a bibliograhy at the back of the article, but it achieves the same end by opposite means. Fetis, Hood, Ellis, tend to stress the multiplicity of results and musical cultures, rather than concentrating on empirical data from specific experiments. Von Bekesy demonstrates a bias toward the place theory but his bias does not appear to affect his willingness to bring forward contradictory results. In particular, he cites both the periodicity and place theories as worthy of additional investigation in his 1966 article "Hearing Theories and Complex Sounds," Journal of the Acoustic Society of America. Terhardt & Zick, Kameoka & Kuriyaga, Pierce, Mathews, Green, Wessel, Risset and Sundberg do not exhibit a bias toward any specific theory of hearing. These authors all cite competing hypotheses and suggest lines of further experimental inquiry into all 3 ear/brain models. Throughout this article the intent has been to present psychoacoustics data as clearly as possible. In many cases this meant extracting experimental results from layers of refutation or from citations buried in bibliographies because this or that psychoacoustician preferred not to bring the inconventient result out into the body of the text, where it might raise embarassing questions. In other cases, viz., Risset or von Bekesy or Pierce, extensive direct quotes of secondary sources were used because these sources offered the most detailed survey of the evidence. Thus the casual reader must be wary of Roederer, Helmholtz, Plomp and other sources widely cited because of the covert (sometimes overt) bias toward this or that tuning or theory or hearing. As mentioned at the outset, acousticians have fared far worse than psychoacoustics researchers in this regard. Backus (1969), like von Bekesy, is biased toward just intonation--but unlike von Bekesy he neglects to mention any of the psychoacoustic experiments which cast doubt on either just intonation as the ideal tuning system or the place theory as the sole explanation of hearing. In the chapter ""Intervals, Scales, Tuning, and Temperament," Backus lavishes 3 pages on just intonation and 2 pages on Pythagorean intonation but only 1 page on equal temperament. No tunings are mentioned other than Pythagorean, meantone, just intonation and equal temperament: there is, for example, no reference to pelog, slendro, the Indian srutis, or any other non-European tuning.. Moreover, Backus buries or is not aware of many psychoucstic data which contradict his view of the ear as simple Fourier analyzer. In part (as mentioned earlier) this is because Backus had the bad luck to publish his book "The Science of Musical Acoustics" just before computers introduced an immense unpheaval into acoustic and auditory research. In part the problem appears to be overt prejudice against acoustic results which do not favor just intonation. As mentioned earlier, texts by Rossing and Hall supersede the acoustics in Backus and the psychoacoustics (where Backus refers to them at all) are incorrect as well as out of date. Thus Backus' entire text should be ignored. Benade (1975) cannot excuse his lapses on the basis of bad timing. In the period 1970-1974 much of the data cited throughout this series of posts was already well known; Benade chooses not only to ignore it, but actually to argue with a number of independently-confirmed results, particularly the universal preference for stretched musical intervals and the accumulated evidence for the periodicity theory. For example: "Experiments by Paul Boomsliter and Warren Creel give us very important information on what a musician actually does about tuning. My discussion in this capter is strongly influenced by these data, although I do not completely accept their published interpretatiojn. Paul C. Boomsliter and Warren Creel, "The Long Pattern Hypothesis in harmony and hearing," J. Mus. Theory, Vol. 5, No. 2, 1961, pp. 2-30, and Paul C. Boomsliter and Warren Creel, "Extended Reference: An Unrecognized Dynamic in Melody," J. Mus. Theory, vol. 7, No. 2, 1963: pp. 2-22. " [Benade, A., "Fundamentals of Musical Acoustics, 1975, pg. 303] In short, Benade agrees with Boomsliter and Creel's claim for "small- integer-ratio" detectors in the ear, but rejects the evidence they provide for the periodicity theory of hearing. Benade's commentary is notable because [1] it is hidden away in a footnote and [2] it ignores the fact that a wealth of additional evidence supports the periodicity theory of hearing-- evidence which cannot be easily explained by the place theory, which Benade espouses. Again: "Everywhere in our experiments we have found indications that our nervous system processes complex sounds coming to it by seeking out whetever subsets of almost harmonically related components it can find." [Benade, A., "Fundamentals of Musical Acoustics," 1975, pg. 68] This statement is as deceptive as it is true. The accuracy of Benade's claim depends on experiments he chooses to perform: and by failing to perform auditory experiments which would cast doubt on the place theory of hearing, Benade creates the impression that no such doubt exists. As has been seen throughout this article, there is ample evidence both to support and contradict the place theory of hearing (and to support and contradict the other two models of hearing as well). By omitting mention of any of this additional evidence, Benade creates a profoundly misleading impression in the unwary reader. The implication of Benade's statement is that all psychoacoustic experiments support the place theory of hearing--entirely untrue, as we have seen. Again: "The situation with tones having harmonic partials is much more straightforward. We have already learned that pitch-matchings between usccessive and superposed tones are in agreement the tones consist of a few strong partials." [Benade, A., "Fundamentals of Musical Acoustics," 1975, pg. 302] The psychoacoustic data do not support this claim. On the contrary: every psychoacoustic experiment since the 1830s shows a distinct and measurable difference betwen intervals heard as "perfect" when played successively and when played simultaneously, with a strong tendency for successive tones to be played wider than simultaneous tones, and a consistent tendency for both categories of tones to be played wider than small-integer ratios. Clearly in this case Benade is unware of (or has chosen to ignore) 150 years of psychouacoustic data. For these reasons Benade's text is unreliable insofar as it bears on psychoacoustics. Some of Benade's acoustic results remain valid, others have been disproven--particularly Benade's discussion of oscillation patterns in woodwinds and his theory of regimes of oscillation for brass instruments. On balance the entire text should be ignored in favor of more detailed and far more accurate treatments by Rossing, Fletcher, Askill and Lord Rayleigh. Rossing and Fletcher's "The Physics of Musical Instruments," and Askill's "The Physics of Musical Sound" remain excellent surveys of the state of the art in musical acoustics. As mentioned, however, little information on psychoacoustics can be gleaned from these texts because psychoacoustics is not their concern. These texts do not cite appreciable amounts of psychoacoustic data and should not be quoted to support this or that tuning or theory of hearing. "Musical Acoustics: An Introduction," by Donald Hall, 1980, contains an accurate precis of acoustics of piano strings, metallohpohnes and woodwinds, as well as good survey of brass instruments, et alii. Hall is strongly biased toward just intonation and he buries or calls into question psychoacoustic data which do not accord with his prejudices. The acoustic portion of Hall's text is impeccable and worth reading, while the section of the book which bears on tuning systems and psychoacoustics is incomplete, outdated, full of errors of omission, and should be ignored. The single best overall survey of psychoacoustic experiments peformed up to the 1960s is Plomp's 1966 text "Experiments In the Tone Sensation." It contains an exhaustive bibliography unmatched anywhere else, and constantly uses extensive direct quotes from the original sources. Plomp exhibits a constant and strong bias toward the periodicity theory; however, he readily admits his prejudice. He is also conscientious in pointing out behaviours of the human ear which are not well explained. Georg von Bekesy is biased toward the place theory; not surprising, inasmuch as his work put the place (Fourier) theory of hearing on a firm foundation. He cites both the periodicity and place theories as deserving further study, however, and (like Plomp) also cites results which contradict all three models of the ear/brain system. "Experiments in Hearing," New York: Robert E. Krieger, 1960 and republished in 1980, is the single best source of references for the place theory of hearing. Harvey Fletcher's "Speech and Hearing in Communication," 1953, is dated but unlike Backus and Benade it is not rendered worthless by overt bias. Better texts now exist (Sundberg, Rossing, Pierce, Terhardt & Zick) but the results Fletcher cites tend to be accurate. Diana Deutsch's 1982 "The Psychology of Music" summarizes key psychoacoustic results by many of reserachers who made the original findings. Most of the contributors are biased toward one or another tuning and the reader must take care to separate experimental results from the conclusions drawn by the various authors. As has been seen, the conclusions of various researchers are on occasion mere opinions, unsupported by the facts. The data cited in Deutsch's compilation are extensive and accurate, although the bibliogpraphies for each section prove distinctly selective. "Psychological Acoustics," edited by E.D. Herbert, is a collection of the original papers in psychocoustics from the 1870s to the 1970s. This is the only text which amasses all the original results in the original authors' own words. Much of the material is now dated, however, and therefore provides an incomplete picture of the ear/brain system. "Auditory Scene Analysis," by Albert S. Bregman, 1990, is a disappointment. It is vague on crucial points and does not cite enough psychoacoustic references. While Bregman does not exhibit major biases toward any specific tuning system, he appears to gloss over many difficult areas of psychoacoustics; viz., the contradictory evidence for various theories of hearing, unexplained ear/brain phenomena, the role of musical illusions in the auditory path, etc. On the whole Bregman's text is useful as a quick overview but should not be cited as a primary source. The next and last post of this series will discuss the higher-level ineraction of tuning, timbre and structural tonality as considered by Rothenberg, Keislar, Douthett and as examined in the work of Pierce, Risset, Sethares, Carlos, et al. --mclaren Received: from eartha.mills.edu [144.91.3.20] by vbv40.ezh.nl with SMTP-OpenVMS via TCP/IP; Thu, 19 Oct 1995 19:38 +0100 Received: from by eartha.mills.edu via SMTP (940816.SGI.8.6.9/930416.SGI) for id KAA07308; Thu, 19 Oct 1995 10:37:43 -0700 Date: Thu, 19 Oct 1995 10:37:43 -0700 Message-Id: <009981E2B053B9DF.5D10@ezh.nl> Errors-To: madole@ella.mills.edu Reply-To: tuning@eartha.mills.edu Originator: tuning@eartha.mills.edu Sender: tuning@eartha.mills.edu