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PDCON:Conference/Pure Data implementation of an ESS-based impulse response acoustic measurement tool: Difference between revisions
PDCON:Conference/Pure Data implementation of an ESS-based impulse response acoustic measurement tool (view source)
Revision as of 16:36, 17 June 2011
, 17 June 2011→Pure Data implementation of an ESS-based impulse response acoustic measurement tool
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Impulse response (IR) measurements for assessing acoustic properties of spaces have been used by acousticians and audio professionals for a long time, with the help of different techniques and test signals. Of these, the Exponential Sine Sweep (ESS) method, successfully advocated by Angelo Farina <ref>A. Farina, "Simultaneous Measurement of Impulse Response and Distortion with a Swept-Sine Technique", pre-print of the 108th AES Convention, Paris (France), 19-22 February 2000</ref>in the last decade, has outstanding properties. | Impulse response (IR) measurements for assessing acoustic properties of spaces have been used by acousticians and audio professionals for a long time, with the help of different techniques and test signals. Of these, the Exponential Sine Sweep (ESS) method, successfully advocated by Angelo Farina <ref>A. Farina, "Simultaneous Measurement of Impulse Response and Distortion with a Swept-Sine Technique", pre-print of the 108th AES Convention, Paris (France), 19-22 February 2000</ref>in the last decade, has outstanding properties. | ||
This paper describes a Pure Data implementation of the ESS method. The need for a Pure Data implementation was due to the lack of features in commercial tools for some practical measurement issues (i.e. PA system speech intelligibility testing in large | This paper describes a Pure Data implementation of the ESS method. The need for a Pure Data implementation was due to the lack of features in commercial tools for some practical measurement issues (i.e. PA system speech intelligibility testing in large spaces). This limitation has caused the authors' frustration while performing professional IR measurements. | ||
The paper proposes a dedicated Pd class [expochirp~], featuring a modified mathematical formulation of the exponential swept-sine signal. Strict boundary conditions have been applied to control not only the frequencies in the chirp but also the phase at any point. A chirp thus generated exhibits minimum ripple in the high frequencies without compromising the frequency range. For the low frequencies ripple, the optimum was found in a rigorously dimensioned time domain window. Mathematical formulae and comparative results will be presented in the upcoming article. | The paper proposes a dedicated Pd class [expochirp~], featuring a modified mathematical formulation of the exponential swept-sine signal. Strict boundary conditions have been applied to control not only the frequencies in the chirp but also the phase at any point. A chirp thus generated exhibits minimum ripple in the high frequencies without compromising the frequency range. For the low frequencies ripple, the optimum was found in a rigorously dimensioned time domain window. Mathematical formulae and comparative results will be presented in the upcoming article. | ||