so that they are not thrown by the latency of these reverberations. Live signal processing While analog audio equipment has no appreciable latency, digital audio equipment has latency associated with two general processes: conversion from one format to another, and digital signal processing (DSP) tasks such as equalization, compression and routing. Digital conversion processes include analog-to-digital converters (ADC), digital-to-analog converters (DAC), and various changes from one digital format to another, such as AES3 which carries low-voltage electrical signals to ADAT, an optical transport. Any such process takes a small amount of time to accomplish; typical latencies are in the range of 0.2 to 1.5 milliseconds, depending on sampling rate, software design and hardware architecture. Different audio signal processing operations such as finite impulse response (FIR) and infinite impulse response (IIR) filters take different mathematical approaches to the same end and can have different latencies. In addition, input and output sample buffering add delay. Typical latencies range from 0.5 to ten milliseconds with some designs having as much as 30 milliseconds of delay. Latency in digital audio equipment is most noticeable when a singer's voice is transmitted through their microphone, through digital audio mixing, processing and routing paths, then sent to their own ears via in-ear monitors or headphones. In this case, the singer's vocal sound is conducted to their own ear through the bones of the head, then through the digital pathway to their ears some milliseconds later. In one study, listeners found latency greater than 15 ms to be noticeable. Latency for other musical activities such as playing guitar does not have the same critical concern. Ten milliseconds of latency isn't as noticeable to a listener who is not hearing his or her own voice. Delayed loudspeakers In sound reinforcement for music or speech presentation in large venues, it is optimal to deliver sufficient sound volume to the back of the venue without resorting to excessive sound volumes near the front. One way for audio engineers to achieve this is to use additional loudspeakers placed at a distance from the stage but closer to the rear of the audience. Sound travels through air at the speed of sound (around per second depending on air temperature and humidity). By measuring or estimating the difference in latency between the loudspeakers near the stage and the loudspeakers nearer the audience, the audio engineer can introduce an appropriate delay in the audio signal