PhD ThesisWhile deep learning (DL) models have achieved impressive results in settings
where large amounts of annotated training data are available, over tting often
degrades performance when data is more limited. To improve the generalisation
of DL models, we investigate \data-driven priors" that exploit additional unlabelled
data or labelled data from related tasks. Unlike techniques such as data
augmentation, these priors are applicable across a range of machine listening
tasks, since their design does not rely on problem-speci c knowledge.
We rst consider scenarios in which parts of samples can be missing, aiming to
make more datasets available for model training. In an initial study focusing on
audio source separation (ASS), we exploit additionally available unlabelled music
and solo source recordings by using generative adversarial networks (GANs),
resulting in higher separation quality. We then present a fully adversarial
framework for learning generative models with missing data. Our discriminator
consists of separately trainable components that can be combined to train the
generator with the same objective as in the original GAN framework. We apply
our framework to image generation, image segmentation and ASS, demonstrating
superior performance compared to the original GAN.
To improve performance on any given MIR task, we also aim to leverage
datasets which are annotated for similar tasks. We use multi-task learning (MTL)
to perform singing voice detection and singing voice separation with one model,
improving performance on both tasks. Furthermore, we employ meta-learning
on a diverse collection of ten MIR tasks to nd a weight initialisation for a
\universal MIR model" so that training the model on any MIR task with this
initialisation quickly leads to good performance.
Since our data-driven priors encode knowledge shared across tasks and
datasets, they are suited for high-dimensional, end-to-end models, instead of small
models relying on task-speci c feature engineering, such as xed spectrogram
representations of audio commonly used in machine listening. To this end, we
propose \Wave-U-Net", an adaptation of the U-Net, which can perform ASS
directly on the raw waveform while performing favourably to its spectrogrambased
counterpart. Finally, we derive \Seq-U-Net" as a causal variant of Wave-
U-Net, which performs comparably to Wavenet and Temporal Convolutional
Network (TCN) on a variety of sequence modelling tasks, while being more
computationally e cient.