The technology relates to processing one or more audio streams. The processing may include segmenting the one or more audio streams into structural components comprising a tonal stream and a transient stream. The tonal stream and the transient stream may be processed and combined to provide an output sound signal. The one or more audio streams may include a first audio stream from a first sound source and a second audio stream from a second sound source. The tonal stream may comprise sound from the first audio stream and the transient stream may comprise sound from the second audio stream. One or more sound effects may be added to the tonal stream or transient stream prior to combining.