Do Not Disturb – Enhanced Noise Cancellation for Gamers
By studying how the brain processes audio, EPOS engineers design headsets for gamers to improve their performance and enhance their gaming enjoyment. As well as traditional audio engineering techniques, the deployment of enhanced noise cancellation technologies can assist the brain in deciphering the audio cues more efficiently and allow the gamer to perform better and for longer periods of time.
While the ear is the organ that captures sound waves, it’s actually the brain that actively interprets and processes those sounds. EPOS’ parent company Demant, along with many universities around the world, carries out research into the way the brain decodes audio, using the insights gained to make the best design decisions for our gaming headsets.
When sound enters the ear canal, the sound pressure waves hit the eardrum, which transfers the vibration to the fluid in the cochlea, a spiral-shaped organ in the inner ear. This triggers the generation of a chain of tiny voltages called neural code which is transported via the auditory nerve to the auditory cortex in the brain.
The first key aspect of engineering a good headset is to ensure the neural code is as clean and accurate as possible, which means delivering to the cochlea the closest reproduction of the real sound as possible.
But much can also be improved by understanding what happens within the brain once good quality neural code is delivered to the brain. Recent study suggests that it is processed in steps. The first, known as the “orient” stage, is where the brain identifies the individual sounds that make up the audio information, taking the overview of the sound scene, and resolving sounds into a foreground. The second stage, “focus”, is where the brain concentrates on deciphering one or more sounds in preference to others.
Illustration: Image showing where orientation and focus takes place in the brain.
Orient and Focus in a game context
A typical game scene will be full of audio cues – gunfire, character speech, environmental sounds such as wind or footsteps. At any single moment, your brain is processing the audio scene, and allowing you to focus on an element within it such as the footsteps, or perhaps team communication in a multiplayer game.
When the signals reaching the auditory cortex are polluted with external noise from outside the headset, this not only spoils the immersion in the game world, but also makes the brain work harder to try to focus on the sounds within the game. Other problems that challenge the brain include poor spatial imaging, lack of balance across the full frequency range, distortion and blurred vocal reproduction, each of which EPOS addresses with specific design considerations.
Enhanced Noise Cancellation to help the brain focus
Noise is an unwelcome part of our modern human environment. There are two main approaches to address this issue with a gaming headset. One is to ensure a good acoustic seal around the ears, with a closed acoustic design and materials chosen for their ability to block noise from entering the interior of the earcup. This is known as passive noise reduction and can be effective at reducing noise in the mid and upper frequencies.
The other technique is known as Active Noise Cancellation, which uses digital techniques to reduce the amount of unwanted noise that reaches the ear canal by altering the signal sent to the headset’s loudspeaker system.
Illustration: A microphone captures the unwanted ambient noise which is processed to create an “anti-noise” signal, similar to a mirror image of the unwanted ambience. When the noise and anti-noise are added together, the signals tend to cancel each other out.
Modern ANC systems all employ the same basic principle. A sound wave has peaks and troughs. If you add a second sound wave, reversing the phase, with the peaks of the second wave corresponding with the troughs of the first, then it will cancel out the first wave and the result will be silence. It’s like adding +1 and -1; the result is zero.
Types of Enhanced Noise Cancellation and ANC
There are a number of different ways to achieve enhanced noise cancellation and ANC. ANC based on the simplest “feed forward” system relies on a microphone(s) on the exterior of the earcup. This captures the environmental noise from outside the headset and subtracts it from the audio entering the earcup.
An alternative ANC technique uses the “feedback” system, which relies on a microphone inside the earcup. This samples only the unwanted noise entering the headset after the passive isolation has done its work and therefore complements it neatly. It works better than feed forward cancellation over a wider range of lower frequencies, and generally gives more reliable results as it is sampling noise within the earcup itself. It’s also less susceptible to problems arising from noise coming from a specific direction.
There is a third noise cancellation system that combines the best of both feed forward and feedback techniques. Unfortunately, this also multiplies the number of microphones required and increases the complexity of the digital processing so is currently limited to the more expensive high-end solutions.
The H3PRO Hybrid headset is the first EPOS gaming headset to include enhanced noise cancellation with ANC as a feature, and it uses the feedback system. The passive noise reduction of higher frequencies offered by this headset is around 30 dB (decibels), but the ANC system further reduces unwanted noise in the lower frequencies which passive noise reduction cannot address effectively by a further 16 dB.
These complementary engineering techniques provide a highly effective solution which supports the reduction of the noise that disturbs our brain’s ability to orient and focus.
In this way, gamers using the H3PRO Hybrid not only have a great experience thanks to the carefully tuned loudspeaker system in their headset that delivers the well balanced, pristine audio the game designer intended them to hear, but also filters out noise that would otherwise add to the cognitive load during both the orient and focus hearing processes.
A clever brain is best supported by clever engineering.