Amazon Product Link: Bose QuietComfort 3 Acoustic Noise Cancelling Headphones * * * * * * * * * * * * * * I have take several business trips lately with more to come. One of my pet peeves is hotel room noise from HVAC… Read more
(Image courtesy of A. Bhatia) Hotels have central heating, ventilation and air conditioning (HVAC) systems which generate noise that may disturb guests’ sleep. The noise propagates through ducts and room surfaces. Individual room air conditioning units may also cause unpleasant noise. The transmission paths in… Read more
I recently flew from Spokane to Seattle, Washington on an Alaska/Horizon Air Bombardier Q400 aircraft, similar to the one in the above image. This model aircraft has two Pratt & Whitney Canada PW150A turboprop engines. I captured the following video during cruise using a Motorola/Android… Read more
Two random signals of particular interest are white noise and pink noise. White noise is a random signal which has a constant power spectrum for a constant frequency bandwidth. It is thus analogous to white light, which is composed of a continuous spectrum of colours.… Read more
I have never formally published any of my papers in a refereed journal or even in an engineering magazine, but others who have done so have referenced my tutorial papers. I am enclosing samples, which include conference papers, etc. – Tom Irvine * * *… Read more
“Shock Diamonds” in the afterburner of a NASA SR-71B Jet * * * Sound pressure levels are limited by the physical characteristics of the surrounding medium. The ambient air pressure at sea level is “one atmosphere,” or approximately 14.7 psi on the absolute scale. The… Read more
The Matlab scripts in SPL.zip calculate the one-third sound pressure level for an acoustic pressure time history. SPL.m is the main script. The remaining scripts are supporting functions. The scripts have options for A, B & C-weighting. See also: Matlab Acoustic Page * * *… Read more
I am working on a commerical aircraft project for which the external fluctuating pressure along the fuselage must be predicted for cruise. I have done a preliminary literature survey. I have loosely assembled some reference data and notes in a paper: Jet Aircraft Fuselage External… Read more
Preliminary notes for acoustic waves: c = speed of sound f = frequency k = wavenumber lambda = wavelength r = radius wavelength is equal to the speed of sound divided by frequency lambda = c / f wavenumber is equal to two pi divided… Read more
Clintonville, Wisconsin is an inland community, adjacent to Lake Pigeon. USA Today reported on March 21, 2012 that a series of mysterious booms have been fraying residents’ nerves. City administrator Lisa Kuss said the booms have roused people from their beds and into the streets… Read more