The phrase 'Head-related Transfer Function', or HRTF, has cropped up with increasing regularity in the last few years, in tandem with the rise of binaural sound, headphone-based immersive audio systems and the development of 'virtual control rooms'.
Essentially, a HRTF is the effect that a person's ear shape and head geometry has on their own unique listening experience, and by identifying it and compensating for it using DSP, things like virtual surround sound and Dolby Atmos can be delivered via headphones with significantly increased realism compared with using generic head measurements.
One way of ascertaining an individual's HRTF has been Genelec's Aural ID Creator app. First launched in 2019, this used the camera on your mobile device to analyse your ear shape and so on, to create a personalised HRTF that could then be used in a number of third-party headphone compensation systems and the like.
Now, Genelec have released a companion Aural ID plug-in (VST, AU, AAX formats) that can read those app-generated HRTFs and apply them directly within your DAW. Once the app has taken your measurements, it uploads them to Genelec's Cloud platform (the same Cloud they use for their GLM monitor optimisation system), which the plug-in can then download. Aural ID can then put it to use in a number of DAW-based scenarios...
First, Aural ID can use your personal HRTF to improve your experience of binaural audio. Secondly, the plug-in includes a library of frequency-correction plots for a number of specific headphone models, which you can use to compensate for any tonal deficiencies in them. Thirdly, it can use your HRTF to give you the impression of listening to a pair of speakers in a room, using your head geometry to accurately reproduce the way in which sound from the left speaker reaches your right ear, and vice versa, with all the attendant complex filtering and delays involved.
Perhaps most impressive, though, is its integration with the aforementioned GLM system. If you use a set of Genelec SAM speakers in your studio — whether it's a simple stereo setup, an 80-speaker Atmos rig, or anything in between — the Aural ID plug-in can take your GLM speaker profile from the Genelec Cloud, combine it with your custom HRTF, and essentially recreate your control room's acoustics and monitoring setup using headphones. The individual nature of all the measurements involved means that the experience should be highly accurate, while the fact that the GLM system takes individual measurements of each speaker in your control room means that you'll even be able to mute and solo individual speakers in your setup, adjust their level, equalisation, listening angle, position in the room and so on.
By combining an end-to-end headphone optimisation system with their own loudspeaker DSP technology, Genelec are aiming to bridge the acoustic gap between studio and remote working, even in the case of immersive audio.
As before, the Aural ID Creator app is free, while the Aural ID DAW plug-in is available on a subscription basis, priced at €490 per year or €49 per month. For more info, check out Genelec's in-depth launch video, below.