You may have come across a listed product specification or even read a discussion about signal-to-noise ratio. Often abbreviated as SNR or S/N, this specification can seem cryptic to the average consumer. While the math behind signal-to-noise ratio is technical, the concept is not, and signal-to-noise value can affect the overall sound quality of a system.

A signal-to-noise ratio compares a level of signal power to a level of noise power. It is usually expressed as a measurement of decibels (dB). Higher numbers generally mean a better specification, because there is more useful information (the signal) than unwanted data (the noise).

For example, if an audio component states a signal-to-noise ratio of 100 dB, it means that the audio signal level is 100 dB higher than the noise level. Therefore, a signal-to-noise ratio specification of 100 dB is significantly better than a specification of 70 dB or lower.

To illustrate, let’s say you’re having a conversation with a friend in a kitchen who also happens to have a particularly loud refrigerator. Let’s also say that the refrigerator is generating 50 dB of hum – consider this the sound – as it keeps its contents cool. If the friend you’re talking to is whispering at 30 dB – consider this the signal – you won’t be able to hear a single word because the hum of the refrigerator is drowning out your friend’s speech.