Re: Sonels and Splash

["Peter Shute" pshute2]

Robin Parmar wrote:=0D
"Certainly a listener would be able to distinguish a lot more than 3 or eve=
n 9 distinct sound source positions... likely more than 20. This makes sens=
e when one considers that we hear a moving source in the stereo field traci=
ng a smooth path, and not jumping from one discrete position to another."=
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Is it possible that the image of a moving source isn't really as smooth as =
it seems, due to our brains filling in the gaps?=0D
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Peter Shute=0D
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Sent using BlackBerry=0D
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From: =0D
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Sent: Mon Jul 16 01:43:30 2012=0D
Subject: [Nature Recordists] Re: Sonels and Splash=0D
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David Brinicombe wrote:=0D
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> A sonel is a sound pixel. The more separate sonels=0D
> you can hear, the better the stereo image.=0D
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It seems that the term "sonel" might be confusing, as it was coined by York=
 University researchers Kapralos et al. for a different purpose. For them, =
sonel mapping is a Monte Carlo method for geometric acoustics, using a part=
icle-based method to overcome the limitations of ray-based techniques.=0D
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I believe instead it is more appropriate to follow Mills' vocabulary of the=
 minimum audible angle (MAA), which refers to the smallest detectable amoun=
t of sound source displacement. Like other JNDs (just noticeable difference=
s) it depends on the frequency of the source. Remarkably, this can be as pr=
ecise as 1 degree (at 500 Hz), but of course this was in a tightly controll=
ed listening environment.=0D
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Using MAA to measure the quality of a location recording is a different mat=
ter -- but is an intriguing possibility! Certainly a listener would be able=
 to distinguish a lot more than 3 or even 9 distinct sound source positions=
... likely more than 20. This makes sense when one considers that we hear a=
 moving source in the stereo field tracing a smooth path, and not jumping f=
rom one discrete position to another.=0D
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Refs:=0D
Kapralos, B., Jenkin, M., and Milios, E. (2006) "Sonel mapping: A stochasti=
c acoustical modeling system". Proceedings of the IEEE International Confer=
ence on Acoustics, Speech and Signal Processing.=0D
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Mills, A. W. (1958) "On the minimum audible angle". Journal of the Acoustic=
al Society of America 30.4, 237=E2=80=93246.=0D
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-- Robin Parmar=0D
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