On Fri, Jun 19, 2020 at 11:12:38PM +0100, Augustine Leudar wrote: > I normally do installation work but lockdown has steered me towards working > on binaural work that can be streamed. Obviously, with speakers, I have a > calibrated system, room treatment etc
> I have a pair of Sennheiser HD600s > that I use but it occurs to me that these kinds of over-ear headphones may > not be best suited for binaural work as there may be some pinna filtering > seeing as the driver is as large as my pinna, so I was thinking earbuds > might be more suitable as they bypass the pinna altogether and you are just > left with the HRTFs In may experience binaural works best with open headphones. Earbuds have a very strong occlusion effect, and there is experimental evidence that this prevents externalisation. Occlusion means that the acoustic impedance as seen by the ear is changed by being in a closed volume. It's why you hear your own voice much stronger when you close the ear canal. It is possible to remove occlusion even with closed headphones, but this requires active systems. Noise cancellation using feedback from within the headphone will do this to some degree as a side effect. Feedforward systems don't. This is an area of active research (in which I'm involved). That said, there's a lot of difference in binaural performance even among high quality open headphones. One factor that seems to have an influence is how well the phase/delay response is matched between the two sides. For some headphones this is intentionally 'randomised', some people seem to prefer that for normal (non-binaural) listening. It's quite simple to test: listen to a mono signal. If the responses are well matched you should get a solid image dead center. If not, even a mono signal will be somewhat 'diffuse'. This is called the 'Tonmeister test' in some circles :-) The argument that open headphones would add a second 'pinna response' to a binaural signal doesn't hold. The whole point of the pinnae is that the response depends on direction, and with headphones that is not the case. What remains is a fixed effect that can be removed by normal equalisation or as part of the design. Ciao, -- FA _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
