Acoustics

The Open University Acoustics Research Group has been in existence for over forty years, carrying out internationally leading research in the fields of environmental acoustics, musical acoustics and the development of acoustical measurement techniques.

Environmental acoustics research carried out by the group includes work on improving the prediction of sound propagation outdoors, producing more effective noise barriers, increasing understanding of acoustic-to-seismic coupling mechanisms, and measuring the acoustic impedance of porous materials. One ongoing area of research is concerned with using acoustic methods to non-invasively determine the properties of soils, with particular focus on enhancing crop yields.

Musical acoustics research topics include investigating the effect of wall vibrations on the playing characteristics of brass instruments, analysing the importance of the bassoon crook to the instrument’s playing properties, monitoring the result of the bending of instrument lead pipes during the manufacturing process, and making bore profile and input impedance measurements on woodwind and brass instruments. One current project within the OU Acoustics Research Group is concerned with investigating, through surveys and experimentation, the problem of pitch drift in choirs during acapella singing. Further details on this project can be found Pitch Drift in a cappella choral singing

The group also carries out work on developing and improving non-invasive techniques for measuring the acoustic impedance, impulse response and internal geometry of ducts such as musical wind instruments, airways and pipeline sections. Such techniques include acoustic pulse reflectometry, a Two-Microphone-Four-Calibration impedance measurement procedure, and capillary-based impedance measurement methods.

Research group facilities include two anechoic chambers, a laser laboratory, a high speed camera, a Laser Doppler Velocimeter, professional quality microphones, as well as a wide range of measuring apparatus and high performance computing equipment.