School of Engineering Department of Electronic and Computer Engineering 132 Projects in Audio Signal Processing - A Multi-Band Approach to Improving Speech Intelligibility Using Wavelet-Based Algorithm Supervisor: CHAU Kevin / ECE Student: DU Tianyuan / CPGBM Course: UROP1100, Fall This research report summarizes some improvements made based on the previous research and conference paper by Yijia Chen et al. from our UROP team, which explored a method for improving the speech intelligibility in the presence of background interference or hearing loss. The method applies a real-time wavelet-based algorithm to separate the speech audio signal into multiple sub-bands, which can then be amplified independently. Since background interference and hearing loss reduce voice intelligibility differently in different frequencies, the multi-band wavelet method allows a more accurate restoration of the original signal, thus resulting in considerable improvements compared to amplifying the whole speech uniformly. The original paper was highly dependent on Google Speech-to-Text recognition as an evaluation means for speech intelligibility. This report supplements further simulations to justify this usage. Nanostructured Chemical Sensors and Sensor Systems Supervisor: FAN Zhiyong / ECE Student: CAI Yuxiang / ELEC Course: UROP2100, Fall Following the process of my projects in the summer semester of 2020-2021 academic year, the work participated by me is mostly based on the same principle of AAO(anodic aluminum oxide) gas sensor. The application of gas sensor in more realistic circumstance is focused compared with my previous work. Although development of AAO gas sensor in my team emphasises on material structure, the design work conducted by me is mostly on PCB layout design, which provides periphery test circuits for severial projects. This circuits create the interface between sensors and development boards. And the final objective is to transmit these datas collected from sensors to the PC and process the information for display on app, which is complished by my groupmates. Besides, some ordinary works are also required to be conducted. For instance, bonding and welding the components is necessary for test whether the design can function as expected. Personally, a large variety of laboratary rules and flows are learned from many senior students in our group.