Techniques for using a trained machine learning (ML) model to detect presence of vehicle defects from audio acquired at least in part during operation of an engine of a vehicle. The techniques include using at least one computer hardware processor to perform: obtaining, via at least one communication network, a first audio recording that was acquired, using at least one acoustic sensor, at least in part during operation of the engine; processing the first audio recording using the trained ML model to detect, from the first audio recording, presence of at least one vehicle defect, the processing comprising: generating an audio waveform from the first audio recording, generating a two-dimensional (2D) representation of the audio waveform, and processing the audio waveform and the 2D representation of the audio waveform using the trained ML model to obtain output indicative of presence or absence of the at least one vehicle defect.