Before the advent of digital audio; most people were not concerned with the very small, but finite delay between when an analog audio signal entered a piece of analog audio equipment and when the corresponding signal exited. Analog delays are extremely short in terms of human perception and are therefore for all practical purposes, non-existent. For this reason, most people would consider analog audio circuitry to have “zero latency.”
By contrast, there are a number of approaches to generating a low-latency monitor mix used in headphone cue mix monitoring during recording and overdubbing with a digital audio system. Due to the nature of human perception, many people consider this to be close enough to zero latency to be workable, with a delay of 1-5 milliseconds. By contrast, analog circuitry delays are typically in the order of one thousand to ten thousand times shorter in time.
Although “workable,” delays in the range of 1-5 milliseconds can still be perceivable when listening through headphones, making it more difficult for a musician or singer to precisely control subtle timing during recording and overdubbing than with a zero latency headphone mix.
- Even if one could argue that a delay in the range of 1-3 milliseconds is perceivable in the right circumstances, in human terms most analog audio circuitry has zero latency.