This is the first iteration of a rain/wind/thunder sound patch made using Pure Data.
Each separate patch uses noise oscillators going through different filters mould the sound to its desired effect.
The ‘Wind’ patch uses a noise oscillator that is fed through a band pass filter with the centre frequency sitting at 150Hz by default but can be moved from 150Hz - 350Hz and the Q (intensity) is also adjustable between 4 - 0.5. There is then another bp filter that is the ‘whistle’ it basically has a really tight frequency bandwidth and sits on the same centre frequency as the other filter, but has a much higher amplitude, accentuating this frequency which gives a whistling effect. The ‘Movement’ slider controls a duplicate of the ‘Whistle’ bandpass filter, but the centre frequency is controlled by a line generator that gradually moves up and down between 200Hz-300Hz, similarly to an LFO. The movement slider controls the speed at which the ‘LFO’ works, or the frequency. The movement can be turned on and off.
There are two rain patches. ‘Rain 1’ is just a noise generator with a filter and volume control, this can be turned on and off. The other rain patch, ‘Rain 2’ is much more complicated and is designed to replicate rain drops. This was achieved by using a noise oscillator and a sine wave oscillator fed through a line generator which acts as an ADSR, with a short attack and a short decay. Then to make it sound random, I used a metro tool that sends a signal at a regular interval, but the interval is defined by a random atom (0-50), which is triggered by another metro atom which is again defined by a random atom. This means that the rain sounds come at completely random times (within the set parameters). The sliders control the velocity/volume of the rain, its frequency (pitch) and the rate at which it comes (lessening the range of the metro).
Finally, the thunder patch… Currently it doesn’t really work. The method that I’ve been trying is using something akin to FM synthesis to make a low rumbling sound, but what happens is the sound is either too low (both frequency and volume) to be effectively audible or it just dominates everything a distorts the whole patch, which is also not ideal. This will be my main focus in improving the patch for the moment, then I’m going to try and improve/add more to the rain sounds.