# intensity of sound/speech

Started by 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.

```