Scientific comparison of earphones

There are many online reviews of earphones that provide non-scientific opinions with comments such as “excellent bass response”, “clear mid-ranges”, and so on, without providing any measured results. As an engineer and a researcher, I find these unsubstantiated claims unsettling. We did a literature review on the internet to find articles that recommended low-price earphones and conducted instrumented testing.

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Sound of crinkling tin foil can cause seizures in cats

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An article published in the Journal of Feline Medicine and Surgery by researchers from the University College London and Davies Veterinary Specialists describes a new condition called feline audiogenic reflex seizures (FARS) that seizures can occur in some elderly cats when they are exposed to certain sounds such as crinkling tin foil and striking a metal spoon on a ceramic feeding bowl.

Read the full article reported in The Telegraph.

Helicopter noise complaint web site opens in LA

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The Federal Aviation Authority has started a helicopter noise complaint system in the Los Angeles county area called the Automated Complaint System (this sounds like a spambot!). The monitoring system uses the  WebTrak site that Bruel and Kjaer bought a few years ago.

The WebTrak system combines GPS data from aircraft movements with noise levels from monitoring stations. Historical data of flight paths and noise levels can be inspected using a web browser.

Distortion important for determining distance of noise source

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Researchers at University of Connecticut Health Center, the University of Rochester, and University of Louisville have published a paper in the Journal of Neuroscience, investigating the ability of a rabbits to determine the distance of a noise source depends on the modulation of the sound.  The researchers inserted tiny microphones inside rabbits’ ears to record the sounds played at several locations. They used these recordings to simulate modulated or unmodulated noise coming from different distances away from the rabbit. Then they played the simulated sounds back to the rabbit, and measured the responses of neurons in the rabbit’s inferior colliculus (IC), a region of the midbrain known to be important for sound perception. When the rabbit heard the simulated sounds, certain types of IC neurons fired more when the sound was closer and the depth of modulation was higher – that is, when there was a bigger difference between the sound’s maximum and minimum amplitude. The neurons fired less when the sound source was further away.

Read the full article on the UConn Today web site.

 

Virtual noise simulation of Heathrow’s third runway

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An acoustic consulting company ARUP has created a 3D virtual sound simulation of the proposed Heathrow’s third runway in their facility called SoundLab. The room is lined with acoustic material to reduce reflections and 12 loudspeakers are positioned on the surface of an imaginary virtual sphere, which are used to generate sound from any direction.

 

Read the full article on wired.co.uk.