processing with High Dynamic Range (3)

This article explores how some different HDR imaging alike techniques can be adopted right into the audio domain.

The early adopters – game developers

In the lately cross-linked article “Finding Your Way With High Dynamic Range Audio In Wwise” some good overview was given on how the HDR concept was already adopted by some game developers over the recent years. Mixing in-game audio has its very own challenge which is about mixing different arbitrary occurring audio events in real-time when the game is actually played. Opposed to that and when we do mix off-line (as in a typical song production) we do have a static output format and don’t have such issues of course.

So it comes as no surprise, that the game developer approach turned out to be a rather automatic/adaptive in-game mixing system which is capable of gating quieter sources depending on the overall volume of the entire audio plus performing some overall compression and limiting. The “off-line mixing audio engineer” can always do better and if a mix is really too difficult, even the arrangement can be fixed by hand during the mixing stage.

There is some further shortcoming and from my point of view that is the too simplistic and reduced translation from “image brightness” into “audio loudness” which might work to some extend but since the audio loudness race has been emerged we already have a clear proof how utterly bad that can sound at the end. At least, there are way more details and effects to be taken into account to perform better concerning dynamic range perception. [Read more…]

what Psychoacoustics is about

If you once listened to MPEG 1 Audio Layer 3 (aka mp3) compressed audio files you’ve already heard some encoding algorithms which are highly based on psychoacoustic principles. But what is that voodoo stuff all about in general? The science of psychoacoustics basically investigates the impact of a physical audio signals property on to the subjective perceived signal (hearing) and whats going on under the hood of that hearing, meanwhile. So it can basically be seen as an input/output model where a certain acoustic stimuli comes in and some sort of perception comes out. On top of that, hearing has not just been seen as a black box but a lot of modelling has already been done to get a better understanding on how hearing is actually performed in our bio-mechanical apparatus and our brain as well. [Read more…]