ERB spectral envelope.

[GOULAS]

Hello friends.


Here is the "ERB spectral envelope". Is it a new way to measure?

 

[GOULAS]

https://drc-fir.sourceforge.net/doc/drc.html

 

[GOULAS]

It seems that the calculation in REW corresponds to the smoothed ERB and not the spectral envelope ERB?

 

[Keith_W]

All of REW's smoothing options are different types of spectral envelope. Read the relevant section in the REW manual here.

To understand what spectral envelope is, maybe an analogy is in order. Suppose you were given a furry dog (the raw measurement) and asked to say whether it is fat or thin. Is it a fat dog with a short fur coat? Or a skinny dog with a thick fur coat? Maybe it's a cat in dog disguise? So you take a garden hose and wet the dog. Now you can see the shape (the envelope) of the animal. You have just applied a "spectral envelope" to smooth out all the fur which is preventing you from seeing the dog.

Obviously, a garden hose is only one type of "smoothing" you could apply. You could also shave the dog or use an X-ray machine. They will all produce slightly different results but in the end you can see the dog.

Some types of spectral envelope are more appropriate for DSP, e.g. psychoacoustic smoothing (more weighting for peaks, less for dips) or variable smoothing (less smoothing for low freqs, more smoothing for high freqs). ERB smoothing mimics what you hear.

 

[GOULAS]

Thanks Keith. In the end, it's almost the same : dogs have the same bones.