  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
