Creating a Multimedia CD-ROM Companion to the Handbook of Music Psychology

Scott D. Lipscomb, Jennifer Willis-Opalenik, and Donald A. Hodges, Institute for Music 
Research, University of Texas at San Antonio

    A number of books are available that survey the field of music psychology. Many of these books are text only (e.g., Radocy & Boyle, 1988), and some have an accompanying cassette or compact disc that provides audio examples (e.g., Dowling & Harwood, 1986). None are currently available that offer audio examples, visual examples, animations, simulations, and demonstrations-all of which are under the interactive control of the user. The purpose of this project is to develop a multimedia CD-ROM companion to the second edition of the Handbook of Music Psychology (Hodges, 1996).
   
The Handbook includes the following 12 chapters:

    The ultimate aim is to have multimedia materials developed for each chapter. Chapter Four was selected as a beginning point, in part because it already contains many illustrations and topics that could easily be complemented by interactive multimedia materials. At its current state of development, the multimedia companion to "Hearing and Music Perception" contains the following components:

Once these components are completed, work will begin on the other chapters.

Units of Chapter Four: Hearing and Music Perception
Hypertext
    The entire text of chapter four has been set up so that users can immediately jump to any page, a feature most useful to those who have a copy of the textbook in hand. For example, a student who has identified a topic for which he would like more information can go directly to that page for additional supplemental materials. Users can also use arrows to navigate forward and backward through the text. All citations are highlighted and clicking on an author's name brings up the full citation. Hotlinks are found throughout the text; clicking on them takes the user to supplementary materials.
The Ear
    One such hotlink takes the user to a unit on the ear. Ibis unit contains a number of illustrations (color and black and white) and micro-electron photographs. Using slide and flat bed scanners, images were imported as PICT files into Director. Salient features of the pictures are identified with "hot buttons" that link to explanatory text and/or to additional images. Users can get information and close up views of anatomical features, such as the cochlea, hair cells, and so on.
Audio Examples
    Many of the complex topics covered in the Handbook are extremely difficult to explain using only text. Therefore, it is absolutely essential that students of music actually experience the sensory impressions discussed in a text that introduces concepts outside of their area of expertise, such as psychology, perception, and cognition. One of the reasons that we decided to begin our multimedia project with examples from Chapter 4 of the Handbook is because of the frequent discussions of psychophysical phenomena found therein, allowing ample opportunity for auditory demonstrations. For example, many references are made to the physical attributes of musical sound (frequency, amplitude, signal shape, and time) and their perceptual correlates (pitch, loudness, timbre, and duration), as well as other complex sensory phenomena for which these fundamental characteristics lay the groundwork. In the hypertext version of the Handbook, students are able to read the same text that exists in the printed version. In addition, however, they are provided opportunities to experience the sounds being discussed with a simple click of the mouse. Textbooks with accompanying cassettes or CDs cannot match this kind of navigational convenience. In essence if students want more information, they just click on one of the hyperlinks.
    Some of these links will simply allow the student to hear a sound file demonstrating the concept expressed in the text. For example, to illustrate how sound energy interacts when two tones are sounded simultaneously, a 1000 Hz tone is sounded for four seconds, followed by a 1004 Hz tone, then both are sounded together. Through the use of a simple auditory demonstration, the effects of "constructive and destructive interference" and the resulting perception of "beats" are made crystal clear. Similarly, to demonstrate how complex sounds result from the combination of sine components, musical instrument sounds will be built one partial at a time so that the student can experience the resulting change in tone quality.
    It will also be beneficial to recreate stimuli used in some of the most significant music psychology research. For example, much discussion has taken place concerning the involvement of a "central processor" in the brain that plays an important role in the human perception of musical sound. Separate experiments by Roger N. Shepard, Diana Deutsch, and Jean Claude Risset assisted in confirming that the auditory processes involved in music listening involve cognitive interpretation. Many textbooks refer to the Shepard tone or Deutsch's tritone paradox-often describing the manner in which these stimuli were created in minute detail-then go on to discuss the relevance of the experimental results. Such presentations often leave students with an incomplete, or even faulty, understanding of the subject matter. With the multimedia companion, a student could read the text and then click on a hyperlink to hear a recreation of these sounds. If "a picture is worth a thousand words," then the value of an auditory example in these contexts is even greater by an order of magnitude.
Simulations and Demonstrations
    Perhaps the most unique and certainly the most challenging aspect of the multimedia companion, is the creation of novel software that will allow the student to explore concepts introduced in the text. Most instructional software used in music education tends to serve the purpose of either a tutorial or "drill and instruction." In contrast, the purpose of the software included on the multimedia CD-ROM companion is to provide the student with an exploratory environment in which she or he can apply the knowledge gained from the reading material in a hands-on manner. Two examples will illustrate the advantages of allowing the student time to experiment with learned concepts.
    In the Handbook, as mentioned above, the student is introduced to the perceived "beats that occur when two tones varying slightly in frequency are sounded simultaneously. The text goes on to explain the crucial role that critical bandwidth plays as the frequencies move farther apart and, as a result, the beats become faster and faster. Using MIDI pitch bend information, a computer program was written that allows the student to control the frequency of one pitch while a second pitch remains constant. As a result, the student is provided an opportunity to explore interactively her or his individual perception of the beats, roughness, and eventual perceived separation of these frequencies into two distinct tones. In this interactive instructional environment, the student is given a greater sense of control in the learning process.
    Software has also been designed enabling the student to create complex signal shapes by determining the amplitudes and phase relationships of each partial. A sound file can then be created at any frequency between 100 Hz and 5 KHz, using the specified signal shape. The student may then view an animation illustrating the motion of an air molecule when encountered by a waveform analogous to the complex signal created.
    These software tools allow the student to take facts learned from the text, apply them to a novel situation, and create a sound object based on the acquired knowledge. It is these higher levels of educational objectives to which our educational institutions should aspire.. With the hypermedia CD-ROM companion, we hope to provide students with a learning tool of inestimable value, as well as a tool with which students can also have a great deal of fun.

References
Dowling, W. J., & Harwood, D. (1986.) Music cognition. Orlando, FL: Academic Press.

Hodges, D. (Ed.). (1996.) Handbook of music psychology (2nd ed.). San Antonio: IMR Press.

Radocy, R. E., & Boyle, J. D. (1988.) Psychological foundations of musical behavior (2nd ed.) Springfield, IL: Charles C. Thomas.