An electronic treatment applied to a sound to 'expand' its dynamic range. Expansion is normally used to reverse the effects of compression in the recording process (e.g. as part of a noise reduction system), but it can also be used on its own to reduce the noise content of a signal by progressively attenuating signals at a low level where noise is most apparent. The action of an expander is similar to that of a noise gate, the two effects often being combined in a single unit. The combination of compression and expansion in a single unit is usually termed a 'compander'. (Source - Richard Dobson (1992). A Dictionary of Electronic and Computer Music Technology. Oxford University Press.)

Traitement électronique appliqué à un son afin d'augmenter son ambitus dynamique. Cette technique est habituellement utilisée pour compenser les effets de compression qui apparaissent lors d'un enregistrement (par exemple dans l'utilisation d'un système de réduction de bruit de fond). Toutefois, cette technique peut aussi être employée pour réduire le bruit d'un signal en atténuant progressivement la dynamique des signaux faibles dans lesquels le bruit est le plus évident. L'action d'un expanseur ressemble à celle d'une noise gate, d'ailleurs, les deux effets sont souvent combinés dans le même appareil. L'association de la compression et de l'expansion dans un seul appareil se nomme habituellement compresseur-expanseur. (Source - Richard Dobson (1992). A Dictionary of Electronic and Computer Music Technology. Oxford University Press.)

Trattamento elettronico applicator al suono al fine di aumentarne l'ambitus dinamico. È una tecnica solitamente utilizzata per compensare gli effetti di compressione che appaiono durante la registrazione (per esempio, durante l'utilizzo di sistemi per la riduzione del rumore di fondo). Tuttavia, tale tecnica può anche essere impiegata per ridurre il rumore di un segnale attenuando progressivamente la dinamica dei segnali flebili nei quali il rumore è più evidente. L'espansione assomiglia a al noise gate (o noise-suppressor), e i due effetti sono spesso combinati nello stesso apparecchio. L'associazione di compressione e espansione in una sola unità viene detta compressore-espansore (compander) (Fonte - Richard Dobson (1992). A Dictionary of Electronic and Computer Music Technology. Oxford University Press.).

An electronic treatment applied to a sound to 'expand' its dynamic range. Expansion is normally used to reverse the effects of compression in the recording process (e.g. as part of a noise reduction system), but it can also be used on its own to reduce the noise content of a signal by progressively attenuating signals at a low level where noise is most apparent. The action of an expander is similar to that of a noise gate, the two effects often being combined in a single unit. The combination of compression and expansion in a single unit is usually termed a 'compander'. (Source - Richard Dobson (1992). A Dictionary of Electronic and Computer Music Technology. Oxford University Press.)

Un tratamiento electrónico aplicado a un sonido para "expandir" su rango dinámico. La Expansión es normalmente utilizada para invertir los efectos de la compresión en el proceso de grabación (por ejemplo, como parte de un sistema de reducción de ruido), pero puede ser empleada también por si sola para reducir el contenido de ruido de una señal atenuando progresivamente las señales de bajo nivel, donde el ruido es más notable. La acción de un expansor es similar a la de una compuerta de ruido (noise gate), siendo ambos efectos frecuentemente combinados en una sola unidad. A la combinación de Compresión y Expansión en una sola unidad se la denomina usualmente "compander".

(Fuente: Richard Dobson (1992). A Dictionary of Electronic and Computer Music Technology. Oxford University Press)