Subject: AI of Fletcher and Galt (1950) From: Hannes Muesch <hmuesch(at)ECE.NEU.EDU> Date: Mon, 1 Nov 1999 11:27:05 +0000Dear Auditory List, I have made available a computer implementation of Fletcher and = Galt=B9s (1950) method for calculating the Articulation Index. It can = be downloaded at http://www.cdsp.neu.edu/info/students/hmuesch Fletcher and Galt's method is an alternative to the standardized = methods [i.e., the ANSI AI (ANSI S3.5, 1969) and the SII (ANSI S3.5, = 1997)]. It goes into much more detail than the standardized methods = and the results are presumably more accurate. Fletcher and his team = at Bell Labs spent about 20 years devising it but, unfortunately, it = has rarely been used.(To my knowledge, in the 49 years after its = publication, the procedure has been used only in 3 published = studies.) This may have to do with the fact that the procedure = involves lengthy computations and geometric construction which made = its application tedious. It is thus understandable that many = researchers and engineers opted to use simplified versions of = Articulation Theory, such as those specified in the ANSI standards. For those who do not want to spend the time reading Fletcher and = Galt=B9s (1950) original work but still want an idea of the basic = principles underlying their procedure, I have written a review that = outlines the general ideas and points out some of the differences to = the standardized AI methods. This review can be downloaded at the = same URL. Fletcher, H., and Galt, R. H. (1950). "The perception of speech and = its relation to telephony," J. Acoust. Soc. Am. 22, 89-151. -- Hannes ________________________________________________________ Hannes M=FCsch Center for Communication and Digital Signal Processing and Institute for Hearing, Speech, and Language Northeastern University Boston, MA 02115 USA phone: (+1) 617 373-5198 fax: x5199 email: hmuesch(at)ece.neu.edu ________________________________________________________