Sinusoidality Analysis and Noise Synthesis

An extension to the phase vocoder method of representing sound in which the “sinusoidality” of spectral energy is estimated during analysis and employed to add noise to a time-stretched phase vocoder synthesis. Three methods of sinusoidality analysis are uesd as well as a sinusoid and noise synthesis method which extends the phase vocoder method. This method allows for the noise characteristics of the original sound to be better maintained during time-stretching.

Paper

Apel, T. (2014). Sinusoidality Analysis and Noise Synthesis in Phase Vocoder Based Time-Stretching. Proceedings of the Australasian Computer Music Conference, pp. 7-12. PDF

Code

pv-noise-synthesis – Octave source code, paper, and sound examples.

Sound Examples

Unless otherwise noted, all samples are mono, 44,100 Hz. Phase vocoder window size is 1024 with an overlap of 4x.

Sine Wave then Noise Stretched x32

Sine then noise:

Sine then noise lengthened 32x by traditional phase vocoder:

Sine then noise lengthened 32x by noise retaining phase vocoder:

2930 Hz and Clicks

2930 Hz sinewave and clicks:

2930 Hz sinewave and clicks lengthened 8x by traditional phase vocoder:

2930 Hz sinewave and clicks lengthened 8x by noise retaining phase vocoder:

Brush Roll

Brush roll:

Brush roll lengthened 8x by traditional phase vocoder:

Brush roll lengthened 8x by noise retaining phase vocoder:

Breathing

Breathing:

Breathing lengthened 8x by traditional phase vocoder:

Breathing lengthened 8x by noise retaining phase vocoder:

Noise and High Soft Tone

Noise and high soft tone:

Noise and high soft tone lengthened 8x by traditional phase vocoder:

Noise and high soft tone lengthened 8x by noise retaining phase vocoder:

Sine Fade into Noise

Sine fades to noise:

Sine fades into noise lengthened 8x by traditional phase vocoder:

Sine fades into noise lengthened 8x by noise retaining phase vocoder:

Pencil Sharpening

Pencil sharpening:

Pencil sharpening lengthened 8x by traditional phase vocoder:

Pencil sharpening lengthened 8x by noise retaining phase vocoder:

Wind

Wind:

Wind lengthened 8x by traditional phase vocoder:

Wind lengthened 8x by noise retaining phase vocoder:

Rain and Thunder

Rain:

Rain lengthened 8x by traditional phase vocoder:

Rain lengthened 8x by noise retaining phase vocoder:

Apple Bite

Apple:

Apple lengthened 8x by traditional phase vocoder:

Apple lengthened 8x by noise retaining phase vocoder:

Snoring

Snoring:

Snoring lengthened 8x by traditional phase vocoder:

Snoring lengthened 8x by noise retaining phase vocoder:

Motorcycle

Motorcycle:

Motorcycle lengthened 8x by traditional phase vocoder:

Motorcycle lengthened 8x with noise method, sine part only:

Motorcycle lengthened 8x with noise method, noise part only:

Motorcycle lengthened 8x with noise retained: