On Wednesday 14th June, Professor Trevor Cox will speak on the subject of ‘A Celebration of Architectural Acoustic Aberrations’ at the University of Manchester. There will be a drinks reception from 5:15pm to 6.00pm followed by the lecture from 6.00pm to 7.00pm. Attendance is free.
Acoustic consultants try to make sure rooms do not have problems such as focussed echoes from domes, excessive reverberation and flutter echoes from parallel walls. But in this paper, I will celebrate these acoustic ‘defects’ and other extraordinary architectural sounds.
The science behind some historical examples, such as the whispering gallery in St Paul’s in London, was solved around a century ago, but others, like the underneath of Echo Bridge in Massachusetts, which was debated in the scientific literature in the 1940s, have never had the physics fully resolved until recently. Some have suggested that Stonehenge should have extraordinary sounds due to the concave arrangement of the stones, but measurements on a 1:12 acoustic scale model of the site show this is unlikely. Mathematicians use billiards to explore dynamical systems, but real-life audio examples are rare. One of those is the abandoned Thurgoland railway tunnel near Penistone, UK that has an extraordinary metallic flutter arising from closed orbits.
The acoustic phenomena play with our perception of sound: in the spherical radome on top of the disused Cold War spy station at Teufelsberg near Berlin, you can whisper into your own ears. Included in the sites to be present will be the disused World War II oil tank which Guinness awarded with the record for the ‘longest echo’. Details of acoustic measurements in the space will be presented, where the reverberation time is 112 seconds at 125 Hz, along with discussions of why it is so reverberant. Remarkable architectural sound effects usually arise by chance, being an accidental by-product of geometry. Using prediction models, the paper will also explore what sound effects could be created if designers deliberately set out to maximise acoustic aberrations.
Trevor Cox is Professor of Acoustic Engineering at the University of Salford where he directs the Acoustic Research Centre. He is a past president of the UK’s Institute of Acoustics and was awarded the IoA Tyndall Medal. His research covers architectural acoustics, psychoacoustics and audio. He has been PI/CI on 10 EPSRC projects on built environment acoustics. Current EPSRC projects include two on machine learning challenges to improve hearing aids. Trevor co-wrote the definitive text on room Acoustic Absorbers and Diffusers (CRC Press). He was an EPSRC Senior Media Fellow. He has presented 26 documentaries for BBC radio including: The Physicist’s Guide to the Orchestra. He won an ASA Science Writing Award for his popular science book Sonic Wonderland. The book describes the oil tank where he broke the Guinness World record for the longest echo. His latest popular science book is Now You’re Talking.