Showing posts with label cognitive. Show all posts
Showing posts with label cognitive. Show all posts

Sunday, January 06, 2013

How Much SNR Bandwidth is Required to (Re)Construct Audio Signals On a Congnitive Level?

I am interested in the cognitive, process-based and technical aspects of storing audio signals at very low amplitude levels, and then seeing what the effect is on a signal, and how such a signal is interpreted in the brain (assuming that the brain has a previous memory of the original signal).

Here is an initial experiment.

Listen to the following source (original) signal. It is a loop that fades out of 40 seconds or so.



This signal was then sent through a series of gains, which applied a uniform gain of between -88dBFS and -94dBFS via the master bus. For reference, the theoretical SNR of a 16 bit yields a maximum of around 6.02 dB x 16 + 1.7 = 98.02 dB.


A file was rendered for each single decibel increment from -94dB to -88dB.These were then normalised to 0 dBFS. You can watch this process below.


You can see the resulting waveforms below. Note how each increase in a single decibel results in a significant increase in signal reconstruction (of course), but there are also noise elements that still contain some signal in the context of the original rhythm or sound - difficult to describe, but when listening to these examples, I find this an interesting thing.