Robinson-Dadson curves

Robinson-Dadson curves

The Robinson-Dadson curves are one of many sets of equal-loudness contours for the human ear, determined experimentally by D W Robinson and R S Dadson, and reported in a paper entitled "A re-determination of the equal-loudness relations for pure tones" in Br. J. Appl. Phys. 7, 166-181 (1956).

Until recently, it was common to see the term 'Fletcher-Munson' used to refer to equal-loudness contours generally, even though the re-determination carried out by Robinson and Dadson in 1956, became the basis for an ISO standard ISO 226 which was only revised recently.

It is now better to use the term 'Equal-loudness contours' as the generic term, especially as a recent survey by ISO redefined the curves in a new standard, ISO 226 :2003.

According to the ISO report, the Robinson-Dadson results were the odd one out, differing more from the current standard than did the Fletcher-Munson curves! It comments that it is fortunate that the 40-Phon Fletcher-Munson curve on which the A-weighting standard was based turns out to have been in good agreement with modern determinations.

The article also comments on the large differences apparent in the low-frequency region, which remain unexplained. Possible explanations are:

* The equipment used was not properly calibrated.
* The criteria used for judging equal loudness (which is tricky) differed.
* Different races actually vary greatly in this respect (possible, and most recent determinations were by the Japanese).
* Subjects were not properly rested for days in advance, or were exposed to loud noise in travelling to the tests which tensed the tensor timpani and stapedius muscles controlling low-frequency mechanical coupling.

See also

*Equal-loudness contour
*Fletcher-Munson curves
*Fletcher-Munson curve *dB(A)
*CCIR (ITU) 468 Noise Weighting

External links

* [ ISO Standard]
* [ Interesting comparisons of ISO with R-D and Fletcher-Munson]
* [ Fletcher-Munson is not Robinson-Dadson]
* [ Full Revision of International Standards for Equal-Loudness Level Contours (ISO 226)]
* [ Hearing curves and on-line hearing test]
* [ Equal-loudness contours by Robinson and Dadson]

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Fletcher–Munson curves — The Fletcher–Munson curves are one of many sets of equal loudness contours for the human ear, determined experimentally by Harvey Fletcher and W A Munson, and reported in a paper entitled Loudness, its definition, measurement and calculation in J …   Wikipedia

  • List of curves — This is a list of curves, by Wikipedia page. See also list of curve topics, list of surfaces, Riemann surface. Algebraic curves*Cubic plane curve *Quartic plane curve *Quintic plane curve *Sextic plane curveRational curves*Ampersand curve… …   Wikipedia

  • Psychoacoustics — is the study of subjective human perception of sounds. Alternatively it can be described as the study of the psychological correlates of the physical parameters of acoustics. Background Hearing is not a purely mechanical phenomenon of wave… …   Wikipedia

  • Phon — The phon was proposed as a unit of perceived loudness level L N for pure tones [ [ jw/dB.html#log UNSW Music Acoustics ] ] by S. S. Stevens. The purpose of the phon scale is to compensate for the effect of frequency on …   Wikipedia

  • Equal-loudness contour — An equal loudness contour is a measure of sound pressure (dB SPL), over the frequency spectrum, for which a listener perceives a constant loudness when presented with pure steady tones. The unit of measurement for loudness levels is the phon, and …   Wikipedia

  • A-weighting — A graph of the A , B , C and D weightings across the frequency range 10 Hz – 20 kHz Video illustrating A weighting by analyzing a sine sweep (contains audio) A weighting is the most …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”