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Question about ITD options in spat5.binaural

Spat
#1

Hello there,

I’m currently using spat in a psychoacoustical study for my master thesis and have a few questions about the ITD options in the spat5.binaural node.

If I set the /itd/type parameter to measurement and the /itd/latenctymode to nolatency with an HRTF set, that doesn’t include ITD cues (the time of arrival part in the HRIRs was cut out beforehand), will I get a binaural rendering without ITD cues, or does the measurement option for the type still adds something to the rendered signal.

maybe a stupid question, but I’m rather new to using spat.
Hope this was clear enough, if someone has further questions, I’ll gladly provide more informations.

Any help would be appreciated and thanks in advance,

Philipp

#2

Hello Philipp,

Not a stupid question. It’s definitely something that is poorly documented, so you’d have to ask.

The ITD type measurement will have an effect only if the HRTF set you are using explicitly contains the delay information. For .sofa files, this is stored in the Data.Delay field, as a broadband delay for the left and right ear separately.
In other words, the spat objects do not calculate any ITD; they just read the value (if any) in the sofa file and apply it.

If you dont know if your sofa file contains any Data.Delay information, you can have use spat5.hrtf.infos to ‘inspect’ the file.

If your sofa file contains Data.Delay information, but you want to remove it, you could use the message /itd/scaling 0 (this should be supported by most spat objects doing binaural processing); this message would multiply any Data.Delay by 0 therefore suppressing ITD cues.

Best,
T.

2 Likes
#3

Hello T,

thank you very much, that saves my study tbh.
The sofa file contains Data.Delay information, but it’s set to zero, so there should be no issue.

Thanks again,
Philipp