Uniformly-Exciting Noise (Bob Stuart )

Subject: Uniformly-Exciting Noise
From:    Bob Stuart  <jrs(at)MERIDIAN.CO.UK>
Date:    Fri, 12 Apr 1996 06:13:22 LCL

To list members.

I would like to add to this thread.

Please note that uniformly-exciting noise (by my
understanding) is a spectrum that produces a constant
excitation with frequency. This is not the same thing as
either:

1. Pink Noise!!!!!
2. Uniformly-masking noise
3. Uniform loudness noise.

The last two differ in the main because internal noise and
detection efficiency are frequency dependent. Pink noise
is simply an inadequate model of auditory-filter bandwidth.

Strictly speaking, there is no one spectrum for any
individual as it varies with intensity (the auditory
filter equivalent bandwidth being level dependent).

In a paper [1] I showed how these different spectra were
related and there are tables that can be used for converting
a threshold to a uniformly-exciting noise.

In [2] I showed how to estimate the spectrum of a special
case, which I called UENTH -- uniformly-exciting noise at
threshold -- which is a noise that can achieve
detectability simultaneously in all bands.

Needless to say, since I live and work in Cambridge UK,
this work is based on ERB not Bark!

I am happy to make data files available.

[1] Stuart, J.R.  "Noise: Methods for estimating
Detectability and Threshold", Journal AES, vol 42, no 3, pp
124-140 (1994)

[2] Stuart, J.R. and Wilson, R.J. "A Search for efficient
Dither for DSP Applications" in 92nd AES Convention, Vienna
(1992) preprint #3334



Bob Stuart: Meridian Audio, Cambridge, England