Page 35 - Spring 2007

The main point of the list of activities above is that it is possible to introduce meaningful hands-on experiences for students that span a number of the subdisciplines of acoustics using only modest equipment. To be sure, it is better still to have a sound chamber (reverberant and/or anechoic), and specialized equipment, but even with a very modest budget, lots can be done. In our case, the only significant addition to the equipment listed above in the introductory acoustics class is an artificial ear. One of the measurement assignments asks students to set their MP3 players to the music type and level they normally employ. We then use the artificial ear to esti- mate the sound pressure level at their ears and ask them to discuss the risk to their hearing from long term listening to the music. Almost without exception, the students are sur- prised to learn that they are listening to music far too loud- ly—typically 85–100 dBA.
Pedagogical techniques
The last decade or so has seen a huge expansion in our understanding of how students learn. With this knowledge, much of which is summarized in How People Learn8 and How Students Learn,9 has come a national push to modify how we teach to correspond better to techniques that foster learning. Thus, the old approach with a lecture during class time, weekly bite-sized homework problems, two or three midterm exams and a final, and a focus on individual accomplishment rather than team experiences is seen as outdated, ineffective, and insufficiently supportive of different learning styles. While STEM courses still use this lecture-style approach the majority of the time, there are signs that change is happening in the classroom even in STEM classes.
Most major academic institutions now support classes
through Web-based educational software. Thus, classes are
able to have an Internet component without great cost to
instructors (neither in time nor dollars). As a result, students
at many institutions have come to expect the class to have a
significant online component. At a minimum, the software
normally provides at least two components of interest to stu-
dents: PowerPoint or other form of course material and a
chat room for those registered in the class. There are those
who argue that putting material presented during class time
on the Web simply encourages students to skip class.
However, the benefits of being able to review the material a
second time are many and the problems of absenteeism can
be dealt with separately (for instance, by taking attendance at
classes and counting attendance toward the final course
grade). The chat room allows students to get to know one
another and to share concerns and approaches to assign-
ments. It can be used as well to share data so that individual
lab reports can include the results from the entire class
instead of the results of a single person or team. A chat room
is also an avenue for students to call attention to information
they have found outside of class that they think might inter-
est the rest of the class. It is thus a type of cooperative learn-
ing and fosters the ability to function on multi-disciplinary
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teams. Acoustics lends itself well to use of an Internet com-
ponent to enhance and reinforce the class. In particular, most educational software allows faculty to include audio files on
the class site. These can greatly enhance the material present- ed during class time by providing more or better demonstra- tions.
Although technology is a major boon to acoustics class- es, there are a number of other aspects of teaching-for-learn- ing that work well with acoustics subject matter. For instance, students tend to learn material more deeply when they are presented with open-ended problems rather than a problem with a single correct answer, because it forces them to think about answers and justify their choices. Additionally, peda- gogical advances encourage greater team experiences so that students may learn from one another as well as from the instructor. Acoustics can deal easily with these advances in pedagogy through use of realistic projects to replace or enhance homework. Such projects almost always have multi- ple correct solutions and lots of follow-on work that can be done. Further, the modern classroom engages students in more active learning, rather than sitting in a classroom and being lectured. Discussions in an acoustics class are quite easy to encourage by bringing in applications of interest.
It is also true that many students in STEM fields are unaware of the career and graduate school opportunities that await their completion of an undergraduate degree. For this reason, many undergraduate programs have developed courses that bring in speakers who talk about their career his- tory and current employment. Students can be relied upon to value these speakers, particularly if they are recent graduates of the program. The use of outside speakers (especially female and minority speakers) in an acoustic undergraduate course is a superb way of demonstrating the diversity of acoustics and of connecting students with potential opportu- nities in their future. Clearly, not all locales have a strong acoustics presence, but at a minimum, virtually all locations have otolaryngologists, sound engineers, speech therapists, and musicians who could be prevailed upon to speak to a class of interested students.
Addressing issues of diversity
The engineering workforce is 93% male and 94% major- ity populations. Unfortunately, the physics workforce is even less diverse and the lack of diversity in most STEM fields is reflected in the membership of the ASA that we take to be a mirror of the acoustics workforce. Clearly there are areas within acoustics that have greater representation of women and minority populations, such as speech and physiological and psychological acoustics, but generally, the acoustics pro- fession has not attracted a widely diverse group of students reflective of the population at large.
There are a few reasons why we should seek to achieve greater diversity in the field of acoustics. First, one could argue that survival of the field requires us to appeal to a broader audience than we have in the past. Indeed, starting in 2000 preschools in the US have been attended by a majority of students who would qualify as underrepresented minori- ties (where underrepresentation specifically refers to STEM fields). Today, the fastest growing population in the US is Hispanic, outpacing the growth of African-Americans, and each of these groups is increasing in size far faster than the
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