Research projects from ISVR Consulting

Most of our consultancy activities are confidential to the client. However clients sometimes give permission for the work to be published.  We also carry out many applied research projects. These projects are often funded by government bodies or the European Union and the findings are widely disseminated. Some projects may be carried out by ISVR Consulting alone, or in collaboration with other organisations or companies. Here are some examples of recent consultancy and applied research projects.
Instrument for Soundscape recognition, identification and evaluation (ISRIE)
A research project to develop an advanced sound meter. This new type of sound meter would not only measure noise levels, but would also characterise the soundscape in a given location and automatically identify or recognise the types of sound source contributing to the total noise environment. The project will cover the development of advanced signal analysis and recognition software and its implementation in hardware. 

Reducing noise from an oil refinery 'cat cracker'
A cat cracker separates heavy oils into gasoline products. There were persistent complaints from the community around a refinery about an irregularly varying noise like a jet aircraft which was traced to a cat cracker exhaust stack.  A detailed study was carried out with field tests on-plant and in the community; scale model tests in the laboratory; theoretical predictions from aerodynamic theory; and a study of atmospheric propagation effects. The cause of the noise was identified as an interaction between the turbulent flow from a valve in the pipe work and an orifice plate downstream of the valve. The irregular variations in the noise were atmospheric effects. Following the investigation, the valve and the orifice were re-engineered giving a reduction in noise levels at the stack tip of up to 14 dB. Noise measurements in the community demonstrated a similar level of noise reduction.  Further information in the published paper (280KB Acrobat/pdf file)
The 'SoundBoat' project
The new EU Recreational Craft Directive sets noise level limits. Carrying out the tests to demonstrate compliance is often a larger problem than meeting the noise limits themselves. The SoundBoat project aims to develop an alternative, simpler test procedure.

The Black Country Forge and Foundry Project
The Black Country Forge and Foundry Project was directed towards the study of noise emission from foundries and forges and the identification or development of practicable, effective means of noise control within the budgets of small companies.  A handbook was produced which provides much guidance on noise control techniques which are also applicable to other industries.

Ear simulators and hearing aid testing
The Ear simulators and hearing aid testing project is being undertaken in collaboration with the National Physical Laboratory as part of the UK Department of Trade and Industry's National Measurement System Programme for Acoustical Metrology.  It covers acoustic couplers, artificial ears, ear simulators and head and torso simulators (HATS). 

Cockpit Voice recorders
Civil aircraft carry two "Black Boxes" - the Flight Data Recorder (FDR) and the Cockpit Voice Recorder (CVR). The FDR records important flight parameters such as altitude and engine settings whereas the CVR records cockpit sounds and crew communications. The aim of the CVR research at ISVR has been to investigate the signatures of violent events on civil aircraft such as those due to rapid decompression caused by structural failure or explosion. An experimental programme has shown that, under some circumstances, the CVR signature can be used to locate the source of the structural failure/explosive device and this is potentially very valuable information for the accident investigators. Further information (1153KB Acrobat/pdf file).

Publications and reports arising from these projects are often available for downloading. See the individual project pages, or look at our available publications list.