The Impact of Audio Effects Processing on the Perception of Brightness and Warmth

Abstract

It is not uncommon to hear musicians and audio engineers speak of warmth and brightness when describing analog technologies such as vintage mixing consoles, multitrack tape machines, and valve compressors. What is perhaps less common, is hearing this term used in association with retro digital technology. A question exists as to how much the low bit rate and low-grade conversion quality contribute to the overall brightness or warmth of a sound when processed with audio effects simulating early sampling technologies. These two dimensions of timbre are notoriously difficult to define and more importantly, measure. We present a subjective user study of brightness and warmth, where a series of audio examples are processed with different audio effects. 26 participants rated the perceived level of brightness and warmth of various instrumental sequences for 5 different audio effects including bit depth reduction, compression and equalisation. Results show that 8 bit reduction tends to increase brightness and decrease warmth whereas 12 bit reduction tends to do the opposite, although this is very much dependent on the instrument. Interestingly, the most significant brightness changes, due to bit reduction, were obtained for bass sounds. For comparison purposes, instrument phrases were also processed with both an analogue compressor and an equalisation plugin to see if any subjective difference was noticed when simulating sonic characteristics that might be associated with warmth. Greater significance was observed when the sound excerpts were processed with the plugins being used to simulate the effects of bit depth reduction. CCS Concepts: • Information systems → Speech / audio search; • Applied computing → Sound and music computing; Media arts; • Computing methodologies → Perception; • Software and its engineering → Semantics.

Context-Aware Intelligent Mixing Systems

“…However, in many contexts, traditional methods are also important and may be growing in importance. Some mixers use terms such as retro or vintage, and distinctive nostalgic sounds are very desirable in many genres [47]. Therefore, in many contexts, both contemporary and traditional paradigms of tool use may be appropriate choices.…”

“…These labels or parameters can be found in audio effects. Similarly there are parameters in effects that can be mapped to emotions that are also suggestive of retro, vintage, or nostalgia [47]. Nostalgia narrows a mixer's set of appropriate choices.…”

“…Mixers refer to a retro digital aesthetic or digital warmth [47]. Within many genres, retro and Lo-Fi aesthetics are embraced as a particular form of artistic expression [29].…”

Word Embeddings for Automatic Equalization in Audio Mixing

“…It is the role of the mixing engineer to understand these descriptors mentioned by the client. Popular semantic descriptors such as warm and bright are easily understood by the mixing engineer [14]. To expand the vocabulary of such descriptors, studies have also tried to create a thesaurus with synonyms and antonyms.…”

Semantic Music Production: A Meta-Study

“…In a series of papers, Brookes and Williams [4][5][6] investigated means to manipulate brightness, warmth, and softness. In [7], different audio effects in music production were assessed to determine how they can manipulate and influence perception of brightness and warmth. [8] developed an effect to independently control brightness and warmth.…”