The human auditory system has evolved to process sounds relevant to survival. But our hearing hasn’t yet evolved to the sounds of modern times, especially urban/industrial noise. Consequently, we often find ourselves exposed to environments that overload the auditory system, which can significantly impact speech understanding, that is, how well and with how much certainty we can receive a message in a given environment. 

In esports, speech understanding can be the difference between winning and losing as it affects the ability to hear in-game sound cues and communication from teammates. When talking about speech understanding we distinguish between signal and noise. The signal is the meaningful information that we want to interpret, whereas the noise is interfering sounds. Theoretically, this relates to speech-to-noise ratio (SNR): the higher the SNR, the easier it is to understand speech. 

Noise also has negative effects on cognitive and task performance, especially for listening, remembering, calculating or conversing. In addition, it can cause harm to our ears and mental health. If our auditory system perceives a noise as a threat it activates the fight-or-flight response of the nervous system, which increases the release of stress hormones in the body. Over time, repeated release of these hormones can be damaging and lead to chronic stress and sleep problems.

So, when it comes to performance optimisation, a player must be aware of both signals and noise and how the latter can be eliminated or reduced.