The level of a signal refers to the volume of a sound. This page will cover things to consider when settings levels, the different decibel scales that you can use to measure the intensity of a sound, and also the psychoacoustics of volume.

There are a number of places that noise can come from and, therefore, there are also quite a few ways in which to improve your signal-to-noise ratio. Here are some:

• Noise can come from the instrument you are trying to record. Placing the microphone at a different angle or pointing at a different part of the instrument may help to reduce noise.

• Room tone is a common source of noise. This includes lights humming, fans etc. that you don’t usually notice but can massively affect your recording. There are plugins available that take a sample of the room tone and then remove that sound from the rest of the recording.

• Noise can come from not only external sources but the recording equipment itself, called self-noise. Using a low self noise microphone and preamp may solve this issue. Another way to reduce self noise is by using balanced cables that are as short as possible. The shorter the cable, the less likely it is that interference will occur.

• Another thing that you can do is move the microphone closer to the sound source, meaning that the signal you want will be louder.

Metering Scales

There are two ways in which you can monitor the level of a signal; peak and RMS. A level meter “gives a visual representation of the incoming audio signal."

A peak meter is “a device for measuring the loudest moments of audio at a specific moment.” Peak metering displays the signal level as it currently is (RMS is a bit delayed) which makes it useful for setting input gain levels and ensuring that the signal isn't going to peak.

An RMS (root mean square) meter, on the other hand, is “a device for measuring the average volume of audio over a period of time.” This meter is useful for "gauging the overall volume of a sound", which is particularly handy when moving on to the mastering stage, due to the fact that it displays the average level of a signal.

Psychoacoustics and Perceived Volume

Psychoacoustics is “the perceived differences in a sound, regardless of actual measurable differences.” It’s all about human perception of sound.

Loudness is a subjective term to describe the objective changes in the amplitude of a sound wave. Decibels actually measure the intensity of a sound and uses a logarithmic scale, rather than a linear one. This means that 60dB isn’t twice as loud as 30dB. In fact, according to some research (not everyone agrees that it’s this simple), the intensity of a sound doubles every 10dB (or 1bel) increase.

It is also important to note that for every 3dB increase, you are doubling the amount of power required from your sound system.

If you fancy learning more about psychoacoustics, here is a very interesting youtube series: