Sound Synthesis II: Inharmonic Analysis
Up to now, we have been analyzing sounfiles with harmonic frequencies. This lab demonstrates how to do non-harmonic analysis of soundfiles to extract (or remove) the most prominent frequencies.
First, lets start with an example noise file created on mambo with the following command:
whitenoise -d 4.0 -a "0 0, 5 1, 95 1, 100 0" source.wavThis will create a soundfile containing 4 seconds of whitenoise with an amplitude envelope that starts at 0 in the beginning of the soundfile, then increases to 1 at 5% into the file, then starts to decay back to 0% starting at 95% of the way into the soundfile.
Notice the parameter SineModel 2 in the analysis file. This indicates to the sms program to analysis the input soundfile inharmonically. The sms program will sort the sinewaves in the input by how loud they are, rather than how they are related to the measured pitch of the soundfile.
The above example extracts up to 100 sinewaves at any given point in time in the input soundfile.
Here are successively few and few sinewaves analyzed from source.wav:
The number of sinewaves extracted from the sound at any given point in the soundfile can be specified as a fuction in the nSines analysis parameter. The following example starts with one sinewave at any given time in the analysis, then at 10% of the way into the file, 2 sinewaves are permitted, then at 20% of the way into the file, 3 sinewaves are permitted, and so on.
Next is an example of extracting imaginary harmonics from a soundfile and stretching them out 64 times the original speed. Frequencies which are harmonics of a pitch between 500 and 520 Hz are extracted from the input whitenoise. Up to 3 harmonics are extracted at any given time.