INTRODUCTION ACOUSTICS

Whether at work, or at home, excess noise can become a real nuisance if left unchecked. Incessant noise is not only distracting, affecting productivity and concentration, but it can manifest in physical ailments. In fact, year on year, the link between excess noise pollution and poor physical health is further established.

Across a number of studies, researchers have demonstrated that people who live and work in noisy environments tend to be more likely to develop harmful health conditions, such as heart disease and high blood pressure. “When it comes to Healthcare environments, acoustics can have a direct affect on the patients recovery: Good acoustic conditions improve patient privacy and dignity, and promote essential sleep patterns. Such conditions are key to healing.” Health Technical Memorandum 08-01.

In light of this growing concern, noise-reducing solutions are becoming increasingly commonplace in domestic and commercial properties. To this end, there is now an expectation that buildings should incorporate solutions that can effectively deal with excess noise.

For many, this endeavour will require an enhanced understanding of acoustics. As such, in this whitepaper, we will highlight the different types of sound that can occur in a building, the relevant regulations applicable to acoustic design and the benefits of installing acoustic flooring solutions.

WHAT IS SOUND?

To begin with, it is important to clarify what we mean by ‘sound.’ Simply put, sound is a form of energy, just like light and electricity, which occurs when air molecules vibrate and move in a pattern called waves, or sound waves.

When a wave is made, the distance between one compression and the next compression is called the wavelength. Wavelengths travel at different speeds, which affects their length and frequency. For example, slower sound waves have longer wavelengths and lower frequencies, whilst quicker sound waves produce shorter wavelengths and higher frequencies. In turn, the frequency of a sound affects its pitch, which can range from high to low.

HOW DO WE HEAR SOUND?

Hearing a sound relies on thousands of tiny hair cells located inside the inner ear. When sound waves enter your ear, they cause a reaction amongst these cells, causing them to rock back and forth. Once this happens, the body converts the vibrations into electrical signals and sends it on to your brain via the hearing nerve. At this point, the brain is able to tell you that you are hearing a sound, as well as what it is.

To help understand the basic science of acoustics, this is a useful glossary of the most important sound-related terms:

Acoustic Treatment	Refers to a collection of products or construction practices, which look to absorb, diffuse or reflect sound waves in a controlled manner. Such products are used to create rooms with more acceptable reverberation time and improved sound character.
Audio Frequency	Signals in the range of human audio audibility, which tend to range between 20 Hz to 20 kHz.
Decibel (dB)	The unit most commonly used to measure sound level. The higher the decibel level, the louder the noise.
Frequency	Refers to the speed of vibration in a sound wave and is measured in Hertz (Hz). Frequency is measured by counting the total number of cycles a repetitive waveform completes in a second.
Reverberation	The tendency of a space to maintain sound energy is quantified by its “reverberation”. Reverberation can be described as a smooth, slowly decaying echo.
Reflection	Reflection of sound occurs when sound waves bounce back off a surface. Echoes are produced as a result of reflected sound.
Sound Absorption	Sound absorption is the loss of noise, when sound waves come into contact with an absorbent material such as walls.