Controllable neural audio synthesis of sound effects is a challenging task due to the potential scarcity and spectro-temporal variance of the data. Differentiable digital signal processing (DDSP) synthesisers have been successfully employed to model and control musical and harmonic signals using relatively limited data and computational resources. Here we propose NoiseBandNet, an architecture capable of synthesising and controlling sound effects by filtering white noise through a filterbank, thus going further than previous systems that make assumptions about the harmonic nature of sounds. We evaluate our approach via a series of experiments, modelling footsteps, thunderstorm, pottery, knocking, and metal sound effects. Comparing NoiseBandNet audio reconstruction capabilities to four variants of the DDSP-filtered noise synthesiser, NoiseBandNet scores higher in nine out of ten evaluation categories, establishing a flexible DDSP method for generating time-varying, inharmonic sound effects of arbitrary length with both good time and frequency resolution. Finally, we introduce some potential creative uses of NoiseBandNet, by generating variations, performing loudness transfer, and by training it on user-defined control curves.
Single-image generative adversarial networks learn from the internal distribution of a single training example to generate variations of it, removing the need of a large dataset. In this paper we introduce SpecSinGAN, an unconditional generative architecture that takes a single one-shot sound effect (e.g., a footstep; a character jump) and produces novel variations of it, as if they were different takes from the same recording session. We explore the use of multi-channel spectrograms to train the model on the various layers that comprise a single sound effect. A listening study comparing our model to real recordings and to digital signal processing procedural audio models in terms of sound plausibility and variation revealed that SpecSinGAN is more plausible and varied than the procedural audio models considered, when using multi-channel spectrograms. Sound examples can be found at the project website: https://www.adrianbarahonarios.com/specsingan/