How could noise (by definition undesirable sound) be something that’s deliberately included in the audio signal path in most synthesizers or be a crucial tool for mostly every sound designer and audio engineer?
Well in this post, i’m going to show some great stuff that can be achieved with the use of noise.
First of all… what exactly are we calling noise?
basically it’s a random signal with inharmonic content. What does that mean? it means
that unlike a musical note, it has no fundamental pitch or partials. Actually, white noise (which draws its name from white light) has the same equal amount of energy within a fixed bandwidth at any center frequency.
Leaving Physics aside, here are some useful stuff that can be done with noise:
1. Synthesize an explosion: the easiest way of designing an explosion sound effect is
to get close to an explosion with a portable recorder a mic and a pair of headphones… synthesize it. For that matter, noise will be the sound source, then we’ll need to filter it, apply envelopes and some kind of distortion (if you are using a synth with an external input and feedback, there you go). Results are really good and experimenting with different parameters will give you different kind of explosions. Our Explosions + more sound effects collection was designed using noise.
2. Synthesize snare drums, shakers and hi hats: as snare drums, shakers and hi hats got lots of inharmonic content, the best way to synthesize them is to use noise as source. For any of the three sounds, we need filters, low pass and high pass. The cutoff point will vary depending of the instrument, especially with the high pass; shakers will have a pretty high cutoff point in the HPF* while snare drums, will have a much lower cutoff point for the HPF- We will also need envelope generators to shape the noise; a simple three stage EG** (attack, decay, sustain), will work. In our Piggy Ni Massive presets collection Snare, hi hat and shaker sounds are included using this technique.
3. Fatten up snare drums: as mentioned before, acoustic snare drums got lots of inharmonic content and one great way to fatten them up is with noise. Imagine you got an acoustic snare drum track and you want to fatten it up, all you need to do is add noise track and insert a gate processor with side-chain capabilities. You will side-chain the gate to the acoustic snare track output, so, every time the snare plays, it will open the gate inserted in the noise track. This is also possible and useful for live situations using ableton live or any other DAW.
4. Synthesize wind or seashore sound effects: noise is a great sound source for these kind of sound design, apply a low pass resonant filter to a noise oscillator, and that’s all you will need. For wind sounds, you will need to add some resonance (or peak) for sibilance and just manually (or with an LFO) vary the cutoff point of the LPF***; for seashore, no resonance is needed but, cutoff point variation, should be slower. Our SCI-FI & Drones sound effect collection includes a wind sound effect designed using this technique.