holiday conundrum ("Richard J. Baker" )

Subject: holiday conundrum
From:    "Richard J. Baker"  <richard(at)PHONETICS.UCL.AC.UK>
Date:    Fri, 11 Dec 1998 11:14:31 -0000

A holiday conundrum courtesy of Sennheiser The following passage is an extract from Sennheisser HD265 instructions. I thought it would be an ideal quote for students to explain in an exam situation! . . . CORRECTION OF LOUDNESS DIFFUSION In a dead or "anechoic" measurement chamber, a multitude of loudspeakers independently emit noise-signals. In the middle zone of the measurement chamber these different pieces of sound information meet and are superimposed in a "diffusion field", where it is no longer possible to tell from which direction each sound has come. These noises will be emitted one after the other at third- octave intervals, alternating over the loudspeakers, and then sent to the headphones. A large number of researchers are at present assessing the difference in volume between spatial noise and the sound in the headphones. The aspired to ideal would be the same level of sound in the headphone as in the diffusion field. In practice, there is a greater atmospheric influence and an improved front-rear (external) detection system. To put it simply, the sound is actually occurring outside the head, is not limited to the space between the ears. . . . TECHNICAL DATA Frequency response 10Hz-30,000Hz (-3dB) 6Hz-35,000Hz (-10dB) Acoustic principle dynamic, sealed Frequency curve diffuse-field loudness equalization . . . * Dr. Richard J. Baker * University College London * Dept. Phonetics & Linguistics * Wolfson House, * 4 Stephenson Way * London NW1 2HE Tel +44 (0)171 380 7403 Fax +44 (0)171 383 0752 Email to AUDITORY should now be sent to AUDITORY(at) LISTSERV commands should be sent to listserv(at) Information is available on the WEB at

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