Patent ID: 6223090
Filing Date: 2001-04-24
Classification: H04R,H04S

Abstract:
A computer controlled closed-loop three-dimensional iterative positioning method for positioning an acoustic manikin for near field head-related transfer function measurements, said method comprising the steps of:providing a selectively positioned audio signal from a sound source;receiving said audio signal at first and second ears of said manikin;transforming time domain representations of said audio signal received by said manikin in a manikin selected axis first position thereof to frequency domain phase and amplitude values;first computing from said frequency domain phase and amplitude values a phase difference between said first ear of said manikin and a phase reference point in an azimuth axis relative to said sound source wherein said phase reference point is said second ear of said manikin and further including rotating said manikin in azimuth such that a determined time delay between said first and second ears is minimized and repeating said transforming and first computing;second computing from said frequency domain phase and amplitude values a phase difference between said first ear of said manikin and a phase reference point wherein said phase reference point is said second ear of said manikin and further including rotating by 180 degrees said manikin about said azimuth axis and rotating said manikin about said selected roll axis such that said time delay between said first and second ears is minimized and repeating said transforming, and second computing steps; andthird computing from said frequency domain phase and amplitude values a phase difference between said first ear of said manikin and a phase reference point wherein said phase reference point is said sound source and further including after said receiving step:ignoring said audio signal at said second ear of said manikin;after said computing step, rotating said acoustic manikin 180 degrees about said azimuth axis and ignoring said audio signal at said first ear of said manikin;computing from said frequency domain phase and amplitude values a phase difference between said second ear of said manikin and said sound source;computing phase difference between said sound source and said first ear before said rotating step and said sound source and said second ear after said rotating step;rotating said manikin about said selected pitch axis such that said time delay is minimized; andrepeating said transforming and third computing steps.