Dear Frederico, Heinrich Kuttruff in Room Acoustics (2009) states the following on IACC:
There is a strong and curious connection between Griesinger’s ‘InterAural Difference or IAD’ and Blumlein shuffling. Allow me to share a link to a recent conference paper (if nothing else, the Blumlein and Gerzon references may help): https://digbyphonic.com/research/rs2025/20251105-DIGBY-HILL-WIGGINS-rs2025-paper.html You could use the Reaper template made available for ‘alt_Blumlein shuffling’ to derive your sum and difference with and without the low-frequency first order shelf eq: https://digbyphonic.com/research/rs2025/RS2025supplements.html As you may be aware, equalization of the difference channel affects the inter-channel timing below the corner frequency of the low-frequency boost: this was Blumlein’s remarkable insight. Side note: After the Abstract in Griesinger’s paper the proposed ‘Diffuse field Transfer Function (DTF)’ is instead shown as ‘DFT’ throughout – common terminology for Discrete Fourier Transform. Quite unfortunate. I hope this helps. Best of luck. // Jonathan J Digby Audio Engineer Researcher +44 7833 151181 From: Frederico Pereira <pereira.frederico@xxxxxxxxx> Dear list, Hoping this message finds you all well. I have two audio signals of music pieces. One is mixed for standard stereo presentation, while the other is a spatial audio mix for binaural presentation. I am looking to find objective measures that could indicate differences in spatial impression, like perceived "spaciousness" / "immersion" / "envelopment". I think a consensual metric would be the Left / Right channels IACC (1/3 oct bands). Besides IACC, I am thinking of using the InterAural Difference (IAD), as suggested by Griesinger ("Griesinger, D. (1999, April). Objective measures of spaciousness and envelopment. In Proceedings of the AES 16th International Conference, Rovaniemi, Finland.). I am here seeking advice on any other suggestions you might have that could be used on the signal analysis of a continuous 2 channel audio signal. Also, are you aware of any available software toolbox that would have any kind of this "spatial impression" analysis conveniently implemented? Thank you for your help, Kind regards, - Frederico -- Frederico Pereira Audio and Acoustics, Perception Interaction and Usability |