Abstract:
Three auditory demonstrations using streaming technology and Java scripts are available via the web. These allow student participation in classic acoustic experiments: octave matching for a single frequency, JND for pitch and a masking task that both use three different base frequencies. Students immediately receive their data for subsequent graphing. The exercises were developed to encourage an inquiry-based approach to the material that focuses on a student’s experience and personal data.
Octave
matching
Just Noticeable
Difference
Auditory masking
Summary:
Our
interest in developing these exercises came through an interdisciplinary
collaboration that resulted when we recognized an overlap in our teaching goals
and needs concerning teaching about sound in physics and psychology.
In particular, we wanted to have students interact with stimuli, tasks,
and data. This enables them to see
for themselves that intuitive theory and scientific data do not always agree.
We
used streaming technology to present stimuli, taking advantage of its easy
availability and low demand on the end-user system. JavaScript was used to
provide the user interface and to return the student’s own data via the web
page once they had finished the task. One of the challenges to writing these
pages was to find phenomena that were robust with single observers and a
relatively small number of trials.
The
exercises were written using an inquiry-based approach.
Specifically, each page was organized around a basic question, and
provided a representative graph of the general intuitive response to the
particular phenomena. For example,
most students think that the absolute volume is going to determine which of two
pitches is audible, not realizing that pitch height plays a critical role.
So for the masking page we show a graph of how those volume-determined
results would appear. After they
have done the task, they are asked to graph their results and discuss what
variables the data reveal as important. By
having the students start with a question, then participate in the task, and
finally graph and analyze their own data, we think we are encouraging the
students to think about how science starts with a question and then uses
experimental methods to begin to develop an answer.
We
use these exercises in two very different classes: a physics of sound course
aimed at non-science majors where the phenomena are used to highlight the
increasing complexity of acoustics, and a perception lab course for psychology
majors where students read journal articles after finishing the demonstration in
order to learn methodology. These exercises and code are available to everyone,
with the hope that others will develop additional interactive exercises.
Note: These pages should run on any PC with a sound card and RealPlayer from www.real.com. Currently, JavaScript is not compatible with the MacOS system, but there is reason to believe that MacOS X will run these pages.