Page 83 - Teaching Innovation for the 21st Century

Further to that, the instruction to download and instal Sonic Visualiser and Audacity was posted as an announcement on the Blackboard (Blackboard 2016) webpage of the course. Deliberately, students were not provided with links to download pages, but were left to their own means to find those and install the relevant packages of both software, with the aim of fostering basic computer literacy skills. Students were given this information two weeks prior to the formal roll-out of the activity to ensure enough time for the setup on their own device. No student reported issues in successfully performing this preliminary step of the work.
The activity was deployed as an online assignment on Blackboard. A dedicated folder containing the study material was created on Blackboard. Instruction videos recorded by the authors and notes produced by the authors were organised into 4 sub-folders as follows:
Step 1:
Download Sonic Visualiser and Audacity (notes, audio files and one 12-minute video which includes a general introduction of the activity).
Step 2:
Visualise and manipulate the recorded sound files with Sonic Visualiser (notes, audio files and four videos all together
of the duration of 80 minutes) to create a *.wav file that
will be used in Step 3; in this sub-folder we also included an introductory video on the cello as a musical instrument and a recap on standing waves, see the screenshot reported in Figure 2(a).
Step 3:
Audacity and data plotting (one 30-minute video). Data manipulation with Audacity includes time integration of the recorded sound to obtain a *.txt file of spectrogram of the frequencies to be plotted separately using a data plotting software of choice.
Step 4:
Wrapping up and submission of the results in the form of a short report, as explained in the next paragraph (notes and one 20-minute video).
The first sub-folder contained the two audio files used for the analysis. These consisted of the audio files of the sound of the open A string of a cello played in the arco (bowed) and the pizzicato (plucked) modes. At the end of the activity students were expected to submit a two-page report. Details on how the report should have been structured were given in sub-folder Step 4 described above. Students were told that the report should consist of the following:
Teaching Innovation for the 21st Century | Showcasing UJ Teaching and Learning 2021
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Full name and student number.
One graph (with axes properly labelled, a legend, etc.) which shows the comparison between the spectrum of the frequencies produced by the A open string of a cello for both arco and pizzicato. This would be similar to the graph reported in Figure 2(b).
A five-column table containing a list of the first 20 vibration frequencies and their decibel level (or loudness) for both arco and pizzicato open A string, as well as the name of the music notes that they correspond to.
Well thought-out and articulated answers to the following questions: a) By comparing the spectrum of vibrational frequencies of arco and pizzicato open A strings, what is the major difference that you notice at higher frequencies? b) Explain why
it is physically possible to have overtones of the vibration of the A open string of a cello which are not A musical notes, but are other notes. By making use of the material developed for this activity, as well as by doing a bit of self-research on the web, students could reasonably be expected to know how to answer these two questions properly.
Students were given two weeks from the formal roll-out of the activity to complete tasks and submit their report. The 2021 cohort performed very well in the activity, with a class average score of 80%.
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