Internal and external sound transmission is the study of sound propagation through building structures. Each building element is required to meet specific noise insulation standards – party walls, floors, glazing, cladding, acoustic doors.
Using CADNA noise modelling software it is possible to model landscapes to detect the propagation of sound through a site from any given noise source. Applications range from rail or road traffic noise through to school playgrounds. The software enable us to predict levels at problem locations and arrive at specifications to counteract any potential complaints and meet the required standards.
STRUCTURE BORNE/VIBRATION ACOUSTICS
Vibration acoustics is the study of sound propagation through structures. The main areas of concern are re-radiated noise levels caused by vibrating structures and noise propagation from construction sites. As a structure vibrates it acts as a loudspeaker creating a sound radiating surface.
By conducting surveys and analysing data using noise prediction methods it is possible to determine the necessary level of vibration isolation required to ensure that noise level on sites built close to railways, motorways etc.. meet the required standards.
Solutions are often found using resilient constructions such as isolated buildings, sprung concrete slabs or resilient wall/ceiling linings.
ROOM ACOUSTICS & COMPUTER MODELLING
Acoustic design is a difficult process, because the human perception of sound depends on such things as decibel level, direction of propagation, and attenuation over time, none of which are tangible or visible. The advent of computer simulation and visualisation techniques for acoustic design and analysis has yielded a variety of approaches for modelling acoustic performance. While these techniques certainly offer new insights into acoustic design, they fail to enhance the design process itself, which still involves a burdensome iterative process of trial and error.
The objectives of this research are twofold: 1) to refine and enhance the accuracy of acoustic simulation techniques while maintaining or enhancing computational tractability, and 2) to address the inverse problem of determining material and geometric parameters for an environment from a description of the desired acoustic performance.
Here at Gillieron Scott Acoustic Design we have now modelled over 40 auditoria including the Roundhouse, The Young Vic, Wavendon, Durham, Peterborough Odeon, Olympic 2012 Velodrome and many more. The results obtained during commissioning have been very encouraging showing an accurate correlation between prediction and actual results.
Using impulse responses from CATT computer modelling it is possible to auralise auditoria to determine possible acoustical problem before they are built using 3DAudioscape and multi speaker array available here on site at our London office.
Due to the advances in computer technology GSAD is now able to offers clients the ability to hear their auditoria before it is built using CATT acoustic modelling software and ambisonic convolution. Impulse responses can be taken from the CATT Model output and played back on a multi speaker array through 3DAudioscape to exhibit the acoustic properties of the model. It is possible for a client to hear what a source on stage will be like in different seats in different acoustical conditions. i.e. Musical, Drama, Opera etc. This gives both GSAD and the client great insight into the expected performance of any given space.
It is also now possible for us to Auralise transmission into buildings with and without isolation to give the client a better understanding of noise pollution in sensitive areas and the advantages of Acoustic isolation.
GSAD are constantly working within large teams on multi projects simultaneously and are at the cutting edge of all aspects of acoustic design using computer modelling to ensure the correct solutions are implemented.
GSAD always seek out the most cost effective solutions to meet design targets and satisfy the client’s aspirations. Construction recommendations are always written using standard building materials where possible to reduce costs and the need for specialist items.
GSAD are members of The Institute of Acoustics, The Association of Noise Consultants and The Theatres Trust and attend seminars and meetings to ensure we design to the latest and highest standards. We develop each building brief with Client and Architect in detail.
We attend a number of meetings and carry out many site inspections to maintain acoustic quality. We do not leave the acoustic outcomes to other team members or contractors and are responsible for achieving the acoustic brief. We engage with each subcontractor before they start on site to make sure they understand our specifications.
GSAD also have impacted on mechanical design elements in the past by suggesting innovative passive ventilation strategies to the design team to reduce both costs and energy usage.
The most recent example of this was an acoustically attenuated passive ventilation system developed for Lauriston School in London leading to the School receiving a large grant (£300,000) for excellent energy performance. The school also collected a RIBA award this year.
Several similar interventions are currently under construction.