Subject: Re: master thesis - audio effect processors - terminology approach From: alexander lerch <lerch.maillists@xxxxxxxx> Date: Tue, 5 May 2009 12:09:23 +0200 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Hi Felipe, I am not sure whether this is really that simple. Just to give a few examples: Where would you sort in pitch-shifters and Auto-Tune, not uncommon audio effects? Even for an exciter the categorization doesn't seem to be obvious to me. And what about non-realtime audio effects such as our harmony plugin vielklang (http://vielklang.zplane.de)? Best, Alexander Felipe Toussaint wrote: > > Dear sound processing experts, > > My name is Felipe Toussaint and I’m studying Terminology in the > /Institut Libre Marie Haps/ (Brussels). I’m currently working on my > master thesis dedicated to the “audio effect processors” that I will > have to deliver on August 19. > > *_Approach_*: terminology > > *_Theme of the master thesis_* : audio effect processors > > *_Languages _*: English and French > > *_Number of terms per language_*: around 55 terms > > *_Objective_* : > > 1. To gather a non exhaustive list of audio effect processors. > 2. To organize them into a hierarchy according to some parameters in > order to get a tree (diagram). > 3. To define those terms according to their places on the tree. > > One of the terminology work aspect is to have the result validated by > experts. This is why I’m appealing to your experience and knowledge of > this precise domain. So at first, I would have liked to have a feedback > on the tree that you will find enclosed. Of course, I’m open to any > criticism and/or suggestions (modification, addition, suppression, etc.) > > Once a consensus found, I will be able to start writing definitions that > will be sent to you in order to have them validated as well. > > If this work arouses your interest, I would be glad to receive your > comments. > > Best regards, > > Felipe Toussaint > > > > *_Tree_* : > > This tree is the final result of a large series of different trees!! > This is a bi-branch tree dividing audio effect processors into two big > groups: AMPLITUDE and TIME domains. They both represent the *action* of > the processor on the signal: to _boost_ and/or _lower_ decibels of the > original signal; to _delay_ the original signal. > > In order to be as precise as possible, I make for each effect processor > an additional tree describing its devices and control parameters (not on > the enclosed document). > > Furthermore, I try to be as neutral as possible while choosing terms, > leaving aside analogue and digital domains and using terms like > “modulator” instead of “LFO”, etc. (don’t hesitate to make any comment). > > 1. *AMPLITUDE domain* : in this category, we find processors that, > in oreder to create a specific effect, will boost and lower the whole > signal or a speicific frequency range. To do so, these processors use a > number of devices (GAIN, FILTER, MODULATOR). A second categorization > comes from these devices. > > a. *GAIN-BASED PROCESSORS* (boost or lower the whole signal) > > i. > amplificateur (amplifier) > > ii. > processeur de dynamique (dynamics processor) > > 1. compresseur (compressor) > > a. limiteur (limiter) > > > i. écrêteur (clipper) > > 2. expandeur vers le haut (upward expander) > > 3. expandeur vers le bas (downward expander) > > a. porte de bruit (noise gate) > > _Devices_ : gain – détecteur de niveau (level detector) > > _Control parameters_ : seuil (threshold) – rapport (ratio) – temps > d’attaque (attack) – temps de relâchement (release) > > *b. **FILTER-BASED PROCESSORS* (boost or lower, pass or cut, a > specific range of frequencies)** > > i. > processeur spectral (spectral processor) > > 1. filtre (filter) > > a. filtre passe-bas (low-pass filter) > > b. filtre passe-haut (high-pass filter) > > c. filtre passe-tout (all-pass filter) > > d. filtre passe-bande (band-pass filter) > > 2. égaliseur (equalizer) > > a. égaliseur paramétrique (parametric equalizer) > > b. égaliseur graphique (graphic equalizer) > > _Devices _: filters > > _Control parameters _: fréquence de coupure (cut-off frequency) – pente > (slope) – gain (gain) – largeur de bande/facteur de qualité (bandwidth/Q > factor) > > *c. **MODULATOR-BASED PROCESSOR* > > i. > trémolo (tremolo) > > 2. *TIME domain:* in this category, we find processors > that, in order to create a specific effect, will delay the input signal. > (Most of them will mix the original version with the delayed one.) > To do so, these processors use different devices (DELAY LINES, FILTERS). > A second categorization comes from these devices : > > *a. **DELAY LINE BASED PROCESSORS :* > > i. > Délai (delay) > > ii. > écho de répétition (slapback) > > iii. double > > iv. écho > (echo) > > v. > réverbération (reverberation) > > _Devices _: ligne à retard (delay line) – régénération (feedback) – > mélangeur (mixer) > > _Control parameters _: temps de retard (delay time) – taux de > régénération (feedback gain) – mélange (mix) > > _Other concepts_ : signal retardé (wet signal) – signal original (dry > signal) > > * > b. **MODULATED DELAY LINE PROCESSORS* > > i. chorus > > ii. flanger > > iii. vibrato > > _Devices _: ligne à retard (delay line) – régénération (feedback) – > modulateur (modulator) – mélangeur (mixer) > > _Control parameters _: temps de retard (delay time) – taux de > régénération (feedback gain) – profondeur (depth) – vitesse (rate) – > forme d’onde (wave shape) – mélange (mix) > > _Other concepts_ : signal retardé (wet signal) – signal original (dry > signal) > > > > *c. **FILTER BASED PROCESSORS (time-varying filters)* > > i. phaser > > ii. wah-wah > > _Devices _: [wah-wah] filtre passe-bande (band-pass filter) – [phaser] > filtre passe-tout (all-pass filter) – modulateur (modulator) - > régénération (feedback) – mélangeur (mixer) > > _Control parameters _: profondeur (depth) – vitesse (rate) – forme > d’onde (wave shape) – taux de régénération (feedback gain) - mélange (mix) > > _Other concepts_ : signal retardé (wet signal) – signal original (dry > signal) > > > > > > ------------------------------------------------------------------------ > Tout ce dont vous avez besoin sur le net et sur votre PC: 100% gratuit ! > <http://www.microsoft.com/belux/fr/windows/windowslive/default.aspx>