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…]

how old are your ears?


quote of the day

It’s not about bending the laws of physics at all, it’s about understanding hearing and utilizing psychoacoustics. – bootsy

hearing is believing


is seeing believing?

The McGurk effect is a compelling demonstration of how we all use visual speech information. The effect shows that we can’t help but integrate visual speech into what we ‘hear’.

This (hopefully) makes you rethink about mixing “visually”.

(thanks to Seppes Santens)

myths and facts about aliasing

A recent trend in the audio producer scene seems to be to judge an audio effect plug-in just by analyzing the harmonic spectrum, which is usually done by throwing a static sine-wave right into the plug-in and then look at the output with a FFT spectrum analyzer afterwards. In this article I’m going to talk about what this method is capable of and where its limitations and problems lie and that aliasing gets confused with a lot of other phenomenons quite often. I’m also clearly showing that this method alone is not sufficient enough to judge an audio plug-in’s quality in a blackbox situation.

a spectrum plot showing noise, harmonic distortion and aliasing

a harmonic spectrum plot showing quantization noise, harmonic distortion and aliasing effects

[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…]

about audio signal coloration

In this comprehensive article some deeper explorations and explanations on this topic are given and at the end a brief but handy definition about audio signal coloration is proposed.  Some tips on mixing can be obtained here as well and – by the way – some myth about equalizing audio in the digital domain gets busted.

Digital image spectrum

Digital imaging spectrum

[Read more…]