octave

Generates normalized A-weigthing, -weighting, octave and one-third-octave digital filters.

Description

This series of M-files generates normalized A-weigthing, C-weighting, octave and one-third-octave digital filters. These type of filters are commonly used in acoustical measurements, for example, in noise control. The implementation is based on the IEC standard for A- and C-weighting filters and on the ANSI and IEC standards for octave and one-third-octave filters. A complete one-third-octave analyzer with graphical output is also provided.

Acknowledgements

This file inspired Reverberation Time Calculator, Nth Octave Frequency Bands, Xlswrite, Goto: Go To A Directory Containing A File, Datalabel, Linelabel, Useful Figure Management Utilities, Getfile, Dragndrop, Timestr, Timetick, Startup Matlab In Last Working Directory, Shadowplot, Goback, Structcompvis, Example: Using Nested Functions For Timers, Nested Function Live Stock Ticker, M Lint Report In Microsoft Excel, Data Space To Figure Units Conversion, Real Time Octave Analysis, Acoustic Tracker (Updated), Data Acquisition Start/Stop Button, Test And Measurement Widgets, Hp 8510 C Demo, Calibrated Spectral Analysis, Dualcursor, Counter Example, Nth Oct Hand Arm & Ac Filter Tool Box, and One Third Octave Filter Bank, Including Additional Inputs And Outputs.

• MATLAB release: MATLAB 5.2 (R10)

[Jorge]

 

[Ali]

Can someone please explain why % All filters below Fs/20 will be implemented after a decimation ?

[Sunil Fernandes]

Thank you much for this.

[Reuben Hale]

CLean accurate and well documented

[Erich Everbach]

Thanks for this excellent tool.

[Michiel Heyns]

I tested the 1/3rd octave algorithm with several sine waves and found it more than accurate anough for analysis. Thank you.

[prem shankar]

 

[Jim Nicholson]

Christophe provides easy to use code of great practical value. Anyone working in acoustics should be aware of this work.

[Irinejus Marmakas]

 

[Dilman de la Fuente]

Fantastic...i can't stop using it, and Boyco...you couldn't be more right...thanks

[Brian Gygi]

 

[Kjell Groendahl]

Great! Saved a lot of coding and reading in standards. Why not include these in the signal processing toolbox?

[Marie-Hélène Lavoie]

Excellent... save me many hours of coding
Bravo

[Rick Stauf]

These routines helped make wind tunnel test successful.

[Ganesh shenai]

good work man.... thanks

[Sreeram Shenoy]

hey too good...solved a major problem for us...thanks a ton

[Herb Singleton]

Note: if you're trying to run adsgn.m or cdsgn.m under GNU Octave (with Matcompat or Octave-forge), the line

[B,A] = bilinear(NUMs,DENs,Fs);

Should be changed to

[B,A] = bilinear(NUMs,DENs,1/Fs);

to account for Octave's syntax.

[Diego Andrés]

Perfect for acoustics. I use it every day!

[Jorge Higuera]

excellent for learning DSP

[Boyko Stoimenov]

BUG Warning!!
It seems this submission is growing in popularity with about 2000 downloads now, and is being used by other subimissions too (Scott Hirsch's 'Real time octave analysis'). Some time ago I found a bug in the 'Leq.m' function which is also used by 'filtbank.m'. Here are the comments from my m-file:

% Leq in decibels is calculated as
% 10*log10(Prms.^2/Pref.^2)
% In the code Prms.^2 is calculated as
% p(i) = sum(x((i-1)*t+1:i*t).^2)/t;
% which is correct, but
% in the next code block Leq is calculated in dB as
% p(idx) = 10*log10(p(idx)/Pref);
% which is correct only for reference Pref=1 (1.^2 = 1)
% For Pref~=1 the code should be
% p(idx) = 10*log10(p(idx)/Pref.^2)

Its really a useful tool. Great!

[William Murphy]

An excellent tool for doing octave and third octave band analysis. We are using it for analyzing different types of noise recordings that are collected in field studies. It provides a means to tranlate FFT transfer functions to more comprehensible data for the layperson.

[William Murphy]

An excellent tool for doing octave and third octave band analysis. We are using it for analyzing different types of noise recordings that are collected in field studies. It provides a means to tranlate FFT transfer functions to more comprehensible data for the layperson.

[Scott Hirsch]

This is a great toolbox - I really like that it cites the ANSII standards. I tell all of my acoustics friends about it!

[Boyko Stoimenov]

Great tool! I use it everyday in my research. Thanks.