In our blog on choosing the right sound systems for your organisation, Dan Morris, Technical Lead at MVS, mentioned how understanding psychoacoustics is fundamental to enhancing and optimising the audio experience. In this blog, we take a deeper look at what that actually means in practice but, firstly, you may be wondering; what is psychoacoustics? Warning: this blog gets technical.
When it comes to sound in AV, it may seem as simple as microphones capturing sound and loudspeakers reproducing it. However, there is much more to it than that. For example, the way in which our brains interpret what we hear. This is where psychoacoustics comes in.
Psychoacoustics is the science of sound perception: how we experience and make sense of audio, not just receive it. Understanding this is essential when designing audio for meeting rooms and video conferencing environments. Getting it right means creating setups that go beyond basic audio reproduction to deliver communication that feels clear and natural for remote and in-person participants.
An overview of acoustics: The Three R’s
Before diving into the specifics of psychoacoustics, it’s worth understanding what happens to sound in the room itself. Even the best microphones and loudspeakers can’t overcome poor room acoustics. Sound behaves in three key ways (the three R’s) that fundamentally affect what reaches your ears:
Reflection occurs when sound waves bounce off hard surfaces like walls, tables, and windows. Too many reflections create a confusing wash of sound that makes speech harder to understand.
Reverb is what happens when those reflections build up, creating that characteristic “echoey” quality. A little reverb sounds natural, but too much makes voices muddy and unclear, especially on conference calls.
Resonance happens when certain frequencies build up in a room based on its dimensions, creating uneven sound where some frequencies are too loud and others disappear. This effect is particularly noticeable at lower frequencies, where it can cause speech to sound boomy, or create problems for newer microphone technologies like beamforming and Automatic Gain Control.
Understanding these acoustic fundamentals helps explain why the room itself plays such a massive role in what your brain receives to process.
With the room’s acoustic behaviour in mind, we can now dive into how our brains interpret the sound that reaches us — and how AV systems can be designed to make use of these principles.
Localised perception: Why the room sounds fine to you but not to them
One of the most important, and most frequently misunderstood, psychoacoustic phenomena in AV design is localised perception: the brain’s ability to compensate for its acoustic surroundings.
When you’re physically present in a room, your brain continuously processes the sonic and spatial information around you, filtering out reflections, background noise, and even competing conversations. This is why a reverberant room doesn’t sound particularly echoey to the people in it, and why you can follow one person’s voice in a noisy bar. Perception adapts to the environment in real time.
This compensation only works if you’re actually in the room. Most microphones and loudspeaker systems can’t capture the full spatial information your brain relies on, which means reflections and unwanted noise will be much more noticeable for remote participants. This is particularly compounded if information is lost via any lossy compression. For example, the compression used in a video conferencing system to restrict bandwidth suitable for sending over the internet (more on this later). This is one of the most common sources of confusion we encounter: clients often struggle to understand why acoustic treatment is necessary when the room sounds perfectly fine to them.
The same principle applies to overlapping speech. In person, the brain can instinctively isolate one voice from another. Remotely, that ability disappears as microphones capture all voices at a similar level, leaving participants without a reliable way to separate them.
When dialling in remotely, your brain still attempts this filtering, but without the necessary environmental data, it can’t succeed. That repeated, unsuccessful effort is a significant contributor to listening fatigue during long calls.
Temporal integration and intelligibility: Not just about volume
Sometimes, when speech is hard to understand, people think the volume is too low. But intelligibility depends on your brain’s ability to integrate sound over time. This is known as temporal integration.
Poor audio quality or background noise can disrupt this process, making speech unintelligible even at normal volume. This is why simply turning up the volume doesn’t always help during videoconferencing calls. Room reflections and reverberation are major culprits here, scrambling the signal before it even reaches the microphone.
Understanding this is exactly why we pay close attention to meeting space acoustics and microphone placement when designing audio solutions. By minimising reflections and controlling reverberation at the source, we can ensure that speech is captured cleanly, so that every participant, whether in the room or dialling in remotely, can follow the conversation without strain.
Haas Panning: Where’s that voice coming from?
In a room with multiple loudspeakers, it’s important that remote voices feel like they’re coming from the right direction, so attendees can naturally locate who’s speaking. The Haas effect achieves this by introducing slight delays between speakers, helping your brain localise where the voice is coming from.
This subtle technique improves meeting equity by anchoring remote voices to the screen or loudspeaker, instead of creating the ‘voice of God’ effect; this is where audio seems to come from nowhere (or everywhere), which can be disorienting and distracting. Unlike point-of-source configurations, where large speakers sit at the front of the room next to the display, a distributed loudspeaker setup using the Haas effect still ensures even coverage across the whole space.
While directionality doesn’t necessarily reduce intelligibility, it does improve listener comfort and can reduce fatigue by creating a more natural experience. In meeting spaces where sound isn’t aligned with its source, this mismatch can become tiring over time, reducing focus and engagement.
Equal loudness (Fletcher-Munson Curve): Why voices can sound different
Our ears don’t perceive all frequencies equally at different volumes. This phenomenon is represented by the Fletcher-Munson Curves, first developed by Harvey Fletcher and Wilden Munson and later refined by D.W. Robinson and R.S. Dadson. While the effect has its roots in the physical construction of the human ear, it has significant practical implications for how we design audio systems.
One of the most important is loudspeaker coverage. Loudspeakers don’t emit all frequencies equally in all directions, and high frequencies typically have narrower coverage patterns. This means careful system design is needed to ensure high frequencies are reaching all participants in the room at a consistent level.
It also informs how we think about use cases. Speech doesn’t require sound reproduction below around 100Hz, so delivering intelligible, comfortable speech doesn’t demand large amplifiers or subwoofers. Music and cinema are a different matter entirely, where reproducing the full frequency range at high volume is essential to the experience.
By understanding this phenomenon, our team adjusts equalisation parameters to suit the environment. For example, if a client wishes to play background music in their office space at a low volume, this may call for a boost in the high and low ends. If the music needed to be louder for a staff event, the equalisation could be configured to reduce these boosts as the volume is increased.
Missing fundamental: How we “fill in” low bass in voice
In conferencing, loudspeakers often struggle to reproduce low bass frequencies. Fortunately, our brains help fill in the gaps. Thanks to a psychoacoustic phenomenon called the missing fundamental, we perceive the full tone of a voice even if its lowest frequencies aren’t physically present, because our brain reconstructs the missing bass from the higher harmonics.
However, relying too heavily on this effect has limits. If too much low frequency is missing, or if the higher harmonics are overemphasised, speech can start to sound thin, harsh, or fatiguing during longer meetings.
That’s why properly designed conferencing audio focuses on balanced frequency response: ensuring that both microphones and loudspeakers capture and reproduce enough of the voice’s natural spectrum to keep speech sounding full, natural, and easy to listen to over time.
Encoding and compression: How platforms use psychoacoustics
Video conferencing platforms compress audio to save bandwidth using lossy compression. However, this isn’t done blindly. Codec designers deliberately exploit psychoacoustic principles, such as the missing fundamental, to make intentional, calculated sacrifices — knowingly removing parts of the audio signal that the brain is wired to reconstruct anyway.
While this keeps calls efficient, it can sometimes introduce artifacts or reduce clarity, especially if the original audio or room acoustics are poor. Ensuring that there is sufficient network bandwidth reduces the likelihood of heavy compression by the platform.
The effects of noise: Adding noise to improve focus
Our brains naturally prioritise dominant sounds, a phenomenon known as auditory masking, where louder sounds suppress our perception of quieter ones nearby. While this can work against us when unwanted noise interferes with speech, it can also be deliberately harnessed.
Extraneous noise negatively impacts intelligibility, and while sources like the hum of air conditioning can be reduced through digital signal processing, there are sometimes trade-offs in audio quality. However, by introducing subtle background noise through a technique known as sound masking, sudden sounds, echoes, and general background noise such as speech, keyboard clicks, and nearby conversations are gently suppressed, turning auditory masking to our advantage.
Modern sound masking solutions, sometimes also referred to as speech privacy systems, such as those from Biamp, can be tailored to different spaces. These are primarily suited to open-plan offices, where masking improves comfort and reduces distraction. Sound masking can also be deployed just outside a meeting room, catching any speech that spills into the surrounding office and rendering it unintelligible to passers-by. This makes it a practical tool for environments where confidentiality is a priority, such as legal offices and government facilities.
Meeting equity: Why psychoacoustics matters
Creating a fair and inclusive meeting environment, often referred to as ‘meeting equity’, means everyone’s voice is clear and natural, no matter where they are in the room—or dialling in remotely.
Understanding psychoacoustics helps us:
- Choose the most appropriate microphones and loudspeakers for the environment and intended usage
- Position loudspeakers and microphones to reduce confusion and echo
- Apply processing that improves clarity without fatigue
- Design spaces that work for all participants, helping to reduce the meeting equity gap between remote and in-person meeting attendees
Final thoughts
Sound is more than waves hitting ear drums. It’s about how our brains make sense of those waves, and how the room shapes those waves before they ever reach us. By leveraging psychoacoustic principles, AV professionals can create meeting spaces and conferencing setups that feel natural, clear, and inclusive for everyone.
If you’re planning a meeting room or video conferencing upgrade, the MVS team is ready to help make sure your audio works for all your participants. From acoustic surveys to complete system design, we work with you, your space, and your budget to create a clear sounding environment.