This week, I spent most of my time working on the design review presentation and design review document. I also thought more about our current noise suppression method, for which we are using a Butterworth filter, spectral subtraction, and adaptive noise filtering. However, based on Professor Sullivan’s advice and my own experimentation with hyperparameters and various notes, the latter two methods do not make a significant improvement in the resulting signal. To avoid any redundancy and inefficiencies, I removed the spectral subtraction and adaptive noise filtering for now. Additionally, I looked more into how we can perform audio segmentation to make it easier to detect pitch and rhythm and found that we may be able to detect note onsets by examining , though this might not work for different volumes without some form of normalization. I will be working with Grace this week to combine our noise suppression and amplitude thresholding code, and more importantly, to work on implementing the note segmentation. Some of the risks with audio segmentation are as follows: noise (so we may need to go back and adjust noise suppression/filtering based on our segmentation results), detecting unintentional extra notes in the transition from one note to another (can be mitigated by setting a rule that consecutive notes must be, say, 100ms apart), and variations in volume (will be mitigated by Grace’s script for applying dynamic thresholding and normalizing the volume). This week, we are also visiting with Professor Almarza from the School of Music to solicit flutists to test our transcription pipeline within the next few weeks.
We are currently on schedule, but we might need to build in extra time for the note segmentation, as detecting note onset and offset is one of the most challenging parts of the project.