Digital signal processing is a valuable practical skill for the contemporary
physicist, yet in physics curricula, its central concepts are often introduced either
in method courses in a highly abstract and mathematics-oriented manner or in lab
work with little explicit attention. In this paper, we present an experimental task in
which we focus on a practical implementation of the discrete Fourier transform (DFT)
in an everyday context of vibration analysis using data collected by a smartphone
accelerometer. Students are accompanied in the experiment by a Jupyter notebook
companion, which serves as an interactive instruction sheet and a tool for data analysis.
The task is suitable for beyond-first-year university physics students with some prior
experience in uncertainty analysis, data representation, and data analysis. Based on
our observations the experiment is very engaging. Students have consistently reported
interest in the experiment and they have found it a good demonstration of the DFT
method.