The Resonics Guide to Room Acoustics

Often perceived as a ‘dark art’, the subject of room acoustics can be quite daunting to anyone approaching it with little or no knowledge. Whilst it’s not untrue that the subject has some complex scientific and mathematical aspects, there are also some basic principles that can be applied in order to create a better understanding about how sound works and why you may have a problem in your particular space. We aim to use this page to demystify some aspects of acoustics – to show you some of the basic theories on acoustics and give you a bit more of an understanding on how to solve your acoustic problem. Our comprehensive acoustic treatment services can also help transform your space into one which is pleasant, comfortable and more productive.

The Benefits of Good Room Acoustics

When lots of sound is travelling to the ear from different directions and a person cannot determine the source, the result is disruption which has a massively detrimental effect on concentration. Good room acoustics ensure that noise is absorbed before it hits a person’s ear, guaranteeing that there aren’t any disruptive effects on concentration. 
Effective Communication relies on good room acoustics. When a room suffers from a problem of excessive noise, the sound of the voice gets lost which results in poor speech intelligibility. Similarly if lots of hard surfaces are causing sound to bounce around the room and cause an echo, the reflections inundate each other and make speech difficult to hear and understand. A room with good acoustics controls the noise levels so that the sound and clarity of the voice is not lost.

Noise can rise to uncontrolled levels when lots of people are talking and moving or there are too many noise sources and not enough sound-absorptive materials in a room.  Good acoustics ensure that noise is absorbed at the right level to afford a comfortable environment in which to work, relax or listen. A feeling of luxury or cosiness can be a component of good acoustics.

It’s no surprise that excessive noise and poor acoustics can have a detrimental effect of productivity. Not only does it affect communication and concentration, unwarranted sound can also effect morale and make workers less productive in their roles. ‘Noise, in addition to causing nuisance and disturbance in an office environment, is a primary cause of reduction in productivity’ (Abbott, 2004). A comfortable acoustic environment is crucial to productivity and morale, particularly in working spaces.
Whether it’s a private doctor’s office, an open plan office, or a restaurant, a certain degree of confidentiality is important in most room types. When there are no sound absorptive materials in a room, privacy between room users or between adjoining rooms can be seriously compromised as there is nothing to stop voices from travelling. Good room acoustics are essential to ensuring privacy.
Audio visual, video-conferencing and tele-conferencing equipment is extremely sensitive to the problem of poor room acoustics and in particular high reverberation. Expensive AV/VC equipment can seriously underperform in a room where there are no acoustic materials to absorb sound bouncing off the walls and other hard surfaces. The result is bounce-back speech carrying through the equipment after the real-time speech has been heard. This makes any communication particularly difficult for the audience to hear as the original message can be shrouded in echo. Good room acoustics are essential to ensuring soundwaves are appropriately absorbed to reduce echo.
Of employees believe they would be more productive if they worked in a less noisy environment.
Sales in a retail shop could increase by 5-10% through acoustic improvement measures.
In schools, up to 70% of the consonants spoken by teachers cannot be heard by pupils.
of office employees say that noise is the single most disturbing factor.

The Most Common Causes of  Poor Room Acoustics


Lots of Hard Surfaces

Hard surfaces such as bare floors and walls and hard furniture  such as wooden or metal tables, chairs and counters all have a detrimental effect on room acoustics. The more hard surfaces in a room, the greater the need for absorption, this is because sound waves are not absorbed by hard materials but instead bounce off these reflective surfaces, creating a noisy and echoey environment.


Multiple Noise Sources

Many noise sources combined contribute massively to poor room acoustics. People talking & moving plus any number of environmental noises such as phones, roads, machinery, air-conditioning & music can combine to create a noise problem. The Cocktail Party Problem is a good example of this – it refers to the difficulty of understanding speech in noisy social settings

DFID_Ecophon Panels

High Ceilings

Higher ceilings increase volume in a room meaning sound is lost in the ‘dead space’ above our heads. They also result in higher reverberation times as sound waves have to travel a long way before they are reflected by a hard surface. Both of these reasons combined mean that high ceilings are bad for room acoustics.

Acoustic Resources & Articles