Introductory signal processing labs based on filterbank applications

Filterbank implementations and simulations can be used successfully in introductory signal processing lab courses by avoiding some of the analytical complexities and focusing on real-world applications. One excellent area is human hearing where the cochlea is well modelled by a filterbank. A lab project that simulates a cochlear implant (CI) combines elements of signal processing with biomedical engineering. Another intriguing application is the decoding of dual-tone multiple-frequency (DTMF) signals used in telephones. Designing a filterbank with multiple bandpass channels to extract signal of interest motivates students to learn filter design, and also provides them with a sense of accomplishment once the whole system is is working. In addition, these filterbank labs can be supported with graphical user interfaces (GUIs) that illustrate how the important components of the system must work together. A comprehensive GUI for the CI simulation is presented along with a GUI tool for filter design. The CI GUI shows the expected signal behavior in the channels after filtering and after detection, as well as having sound input-output, so that students can listen to the key signals.