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intensity of sound/speech

Started by stromhau January 6, 2007
Hi,

I am trying here because it seems like there are a lot of experts knowing
all sort of DSP ++. Have found a lot of answers to othert questions.

My problem is to calculate intensity contours of a speech waveform with
amplitude +1/-1 expressed in a desibel scale.
I have spent 5-6 hours of googling without results.

The intensity is defined as : sound intensity = sound power / (4 pi R2)
, but here we have a radius that i cant get to fit in.
The intensity of a sound wave depends on how far we are from a source.
The only thing i have is the waveform and no references to a distance.

If i have managed to get this intensity i think i could have used this :

sound intensity level = LI = 10 log ( I / I0 ) , where I0 =  I0 = 10-12
W/m2

to get the desibel scale.


I have used some feature extraction in an application called Praat that
does this intensity tracking based on a waveform.

The algorithm used there says ; The values in the sound are first squared,
then convolved with a Gaussian analysis window (Kaiser-20; sidelobes below
-190 dB). The effective duration of this analysis window is 3.2 /
(minimum_pitch), which will guarantee that a periodic signal is analysed
as having a pitch-synchronous intensity ripple not greater than our 4-byte
floating-point precision (i.e., < 0.00001 dB).

This algorithm i really dont understand.

The values that are squared is it the amplitudes of the waveform ?
what does :Gaussian analysis window (Kaiser-20; sidelobes below -190 dB)
mean?
It also seems that this calculation is done after the pitch extraction as
the analysis window is 3.2/minimun_pitch

Any matlab experts that can provide code for this algorithm ?

Can anybody explain it to a DSP newbie or is it other easier methods to
calcultate the instensity contour of the waveform ?


I really hope anybody will help me out here :)

Tommy,
Norway


> >Hi, > >I am trying here because it seems like there are a lot of experts
knowing
>all sort of DSP ++. Have found a lot of answers to othert questions. > >My problem is to calculate intensity contours of a speech waveform with >amplitude +1/-1 expressed in a desibel scale. >I have spent 5-6 hours of googling without results. > >The intensity is defined as : sound intensity = sound power / (4 pi R2) >, but here we have a radius that i cant get to fit in. >The intensity of a sound wave depends on how far we are from a source. >The only thing i have is the waveform and no references to a distance. > >If i have managed to get this intensity i think i could have used this : > >sound intensity level = LI = 10 log ( I / I0 ) , where I0 = I0 = 10-12 >W/m2 > >to get the desibel scale. > > >I have used some feature extraction in an application called Praat that >does this intensity tracking based on a waveform. > >The algorithm used there says ; The values in the sound are first
squared,
>then convolved with a Gaussian analysis window (Kaiser-20; sidelobes
below
>-190 dB). The effective duration of this analysis window is 3.2 / >(minimum_pitch), which will guarantee that a periodic signal is analysed >as having a pitch-synchronous intensity ripple not greater than our
4-byte
>floating-point precision (i.e., < 0.00001 dB). > >This algorithm i really dont understand. > >The values that are squared is it the amplitudes of the waveform ? >what does :Gaussian analysis window (Kaiser-20; sidelobes below -190 dB) >mean? >It also seems that this calculation is done after the pitch extraction
as
>the analysis window is 3.2/minimun_pitch > >Any matlab experts that can provide code for this algorithm ? > >Can anybody explain it to a DSP newbie or is it other easier methods to >calcultate the instensity contour of the waveform ? > > >I really hope anybody will help me out here :) > >Tommy, >Norway > >
>
Sorry for the double post. No idee why it happened.