Have you ever covered your ears with your hands to protect yourself from loud noise? That’s the closest to natural hearing protection that we’ve got, but just how much does it reduce the sound pressure level reaching your ear? And what’s the best method? This experiment aims to find out.
In our previous reverberation time measurement tutorial an impulse response, created by bursting a balloon, was used as the measurement signal. This is a quick and simple method of carrying out a reverberation time measurement, but may not be the most accurate method. In this tutorial we will look at an alternative method that can provide improved results.
The World Health Organisation states that loud noise is the single biggest preventable cause of hearing loss in the UK. Due to advances in portable media player technology, users are now able to store and play music for much longer. Due to this, there is a huge potential risk for overexposure to noise using these devices. It is now estimated that over 4 million young people in the UK are suffering with the effects of noise induced hearing loss from listening to amplified music in the UK.
Solent Acoustics has recently taken delivery of an impedance gun kit from Microflown, used for the in-situ measurement of sound absorption coefficient.
The kit contains the impedance gun itself, which is constructed of a loudspeaker and PU Probe (for the measurement of both pressure and particle velocity), and a Scout V2 USB data acquisition system. Software provided by Microflown allows for the calculation of acoustic absorption coefficient from the measurement of pressure and particle velocity, which also allows for measurement of acoustic intensity.
Solent Acoustics has recently taken delivery of a brand new intensity probe kit from Brüel & Kjær. The kit comprises of a phase and amplitude matched, class 1 microphone pair (Type 4197), a 2 channel preamplifier system for housing the microphones, a calibrator adapter, windscreen, extension stem, earphones, tape measure and carrying case. The system is compatible with the Hand-held Sound Intensity System Type 2270 for measuring sound intensity.
25th September 2014
This meeting examined aircraft acoustics from the perspective of issues concerning both the military and civilian sectors.
At the end of the meeting there was a tour around the spectacular QinetiQ Noise Test Facility, including one of the largest anechoic chambers in the world.
Research carried out by the Massachusetts Institute of Technology, along with Microsoft and Adobe, has been used to extract audio data from video by analysing the tiny, imperceptible vibrations that occur in objects when they are subject to a sound.