Re: equal loudness calculation

[Jose-Javier Lopez <jjlopez@xxxxxxxxxxx>]

> in this case, I don't want to filter a sound, but simply scale its
> amplitude.
> Or is there a way to make the formula itself efficient by
> implementing it as a filter?

If you have your data in freq domain, just use the equation for weighting.
In this case you don't need to filter in time domain.

JJ



----- Original Message -----
From: "Julian Rohrhuber" <rohrhuber@xxxxxxxxxxxxxx>
To: <AUDITORY@xxxxxxxxxxxxxxx>
Sent: Monday, April 18, 2005 12:18 PM
Subject: Re: [AUDITORY] equal loudness calculation


> >This is the analitic equation for A-Weighting.
> > http://www.beis.de/Elektronik/AudioMeasure/WeightingFilters.html#A-Weighting
>
>
> thank you, this is quite exactly what I was looking for.
>
> > Just, pass it to Z domain and use "a" and "b" coef. in a IIR filter.
>
> in this case, I don't want to filter a sound, but simply scale its
> amplitude.
> Or is there a way to make the formula itself efficient by
> implementing it as a filter?
>
> > Very efficient !
> >
> > JJ
> >
> >
> >
> > ----- Original Message ----- From: "Julian Rohrhuber"
> > <rohrhuber@xxxxxxxxxxxxxx>
> > To: <AUDITORY@xxxxxxxxxxxxxxx>
> > Sent: Tuesday, April 12, 2005 4:25 PM
> > Subject: [AUDITORY] equal loudness calculation
> >
> >
> > >  I'm looking for a computationally efficient way to do a frequency
> > >  dependent amplitude compensation. The emphasis is much less accuracy
> > >  (especially not for different loudness levels) but more a reasonable
> > >  approximation - maybe a polynomial.
> > >
> > >  Any hints?
> > >
> > >  --
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >  .
>
> --
>
>
>
>
>
>
>
>
> .