Attack and release are specified in milliseconds, and correspond to how quickly the compressor should vary the output gain in response to the signal exceeding or falling below the threshold. These adjustments can be linear or log based.The desired output level is not achieved until the input has exceeded the threshold for the time specified by attack, and similarly returns to unity only after the input is under the threshold for the time specified by release.For more information, see Equalization and compression in Overview of SHAPE.