Digital audio recording offers a number of improvements over analog recording equipment. But the biggest drawback of recording using a computer or digital audio recorder is latency. Latency refers to the delay in sound output or recording caused by the inherent limitations of a digital system. Latency has an immense impact on recording digital audio, as it can cause inconsistencies in timing and errors or glitches in sound processing.
Why Does Latency Occur?
In order to record audio, the computer has to convert analog sound waves into digital data. Just like it would take you a few moments to write down what a speaker is saying during a lecture, there is a delay between the time a sound enters a microphone and when it is recorded. With computers, this delay is often measured in milliseconds. For most purposes, such as adding narration to a video or video chatting, this latency is hardly noticeable. But when it comes to recording music, those few milliseconds can mean the difference between hitting a groove and playing off beat. Likewise, if you are using a MIDI instrument, there will be a slight delay between the time you press a key and when you hear the sound.
How do you reduce latency?
The first step to reducing latency is to eliminate as much strain on the processor as possible. When recording, it’s best to close all other programs and other processes that aren’t essential to recording. The less inhibited your processor is, the faster it can process sound.
Another key to reducing latency is buffering. Buffers allow audio to be loaded ahead of time so it can be played back in real time. If the buffer is too small, you’ll experience glitches or gaps in recording or playback. However, too large of a buffer will increase latency, since audio must pass through the buffer before being played back or recorded.
The biggest cause of latency when recording is due to monitoring latency. When recording multiple tracks or along with a click track, there will be a delay in the output of the sound as well as a delay in recording. As such, you’ll have twice the latency. This can be reduced through zero latency monitoring interfaces, which bypass software buffers—however soft synths and MIDI instruments cannot be used with zero latency monitoring.
You can reduce latency to acceptable levels by investing in an audio interface or a high performance sound card. Audio interfaces with zero latency monitoring help reduce delays, but they also alleviate strain on your CPU, which improves performance. It’s also important to have the latest drivers and audio recording programs, since the more efficient the software, the less delay and CPU consumption you’ll experience.
In conclusion, there’s no such thing as zero latency digital recording. There will always be a slight delay between the time a sound is triggered and when it is produced and between when a sound is produced and when it’s recorded digitally. However, as technology improves and computers and sound cards become faster, this latency can be reduced to negligible levels.