Tag: Acoustics
Malta’s Hypogeum of Ħal-Saflieni
The UNESCO World Heritage Site at Paola, Malta has special significance due to its remarkable acoustic properties. The Hypogeum of Ħal-Saflieni is an underground cave system covering around 500m² on 3 levels, with various inter-connecting corridors and passageways that lead to a number of small chambers, built between 3000-2500BC. The cave system was re-discovered in 1902 and since then there has been particular interest in one of the rooms, named the “Oracle Chamber”. The space is said to amplify voices dramatically, with certain frequencies resonating enough to be felt through the body.
Tutorial: Measuring Reverberation Time
The reverberation time of a room has a distinct effect on its suitability for different tasks, in this tutorial we will look at the different methods of measuring reverberation time and what the results can show us.
The first step in carrying out a reverberation time measurement is choosing the method. There are a number of different methods available to us however some will require specialist equipment that the average person will not have access to (look out for follow up tutorials for these!). The simplest method involves creating and recording an impulse response.
Perceptually optimised sound zones
Last month we had the pleasure of an invitation to the University of Surrey, to attend a presentation and demonstration of some really interesting research on sound zones.
The team, headed by Dr Philip Jackson, was supported by Bang & Olufsen, and is a joint effort from the Centre for Vision, Speech, & Signal Processing, and the Institute of Sound Recording within the University.
Can a pill prevent hearing loss?
Some very interesting work by Dr. Kathleen Campbell is revealing that there may be potential to produce an orally induced drug that could act as a preventative to hearing loss.
Acousto-Optic Scanning: Seeing Sound
Being able to visually interpret sound would be an extremely useful function, one that could aid people in the understanding of wave propagation and how those waves interact with each other. As well as this, visualising sound could aid loudspeaker design as manufacturers are able to more accurately study the interference patterns that determine the directivity and frequency response of their products.
Researchers at the National Physical Laboratory seem to have done just that, using a scanning laser Doppler vibrometer that can measure the minute changes in optical phase as the laser passes through an acoustic field.
The Acoustics of the Epidaurus Theatre
Situated across the Saronic Gulf from Athens, the ancient greek city of Epidaurus is home to a 15,000 seat theatre that was once used for lavish dramas and banquets. It is well known for having remarkable acoustic properties, allowing voices from the stage to travel clearly to the very top row of seats, without amplification.
Researchers from Georgia’s Institute of Technology have discovered the science behind the Greek theatre’s incredible acoustics, carrying out in-situ measurements and using computer modelling to determine what effect the steep incline and unique layout have on the propagation of sound.
