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Re: Roots of the term "gammatone"

On 28/03/2012 09:05, Tamas Harczos wrote:
I am looking for the first time use of the term "gammatone". 
I believe, as I wrote in our ISH paper of 1992 that "It was introduced by Aertsen and Johannesma (1980) and used by de Boer and de Jongh (1978) to characterise 'revcor' data from cats." The full references are below.

What I remember from talking to Egbert de Boer is that he coined the term in the late 1970's but did not use it in de Boer and de Jongh (1978). A little later, Aertsen used it in the paper with Johannesma. Johannesma originally developed the function in 1972 but did not name it in that paper. The Aertsen and Johannesma (1980)paper is on grass frogs and it is in Biol. Cybern. which may help explain why there is a mystery about where the name came from.

For those interested in the development and use of gammatone and gammachirp auditory filters, we provided an overview as Appendix A of

Patterson, R.D. , Unoki, M. and Irino, T. (2003). "Extending the domain of center frequencies for the compressive gammachirp auditory filter." J. Acoust. Soc. Am. 114(3), 1529-1542.

I can provide a pdf of the paper on request.

Best regards, Roy Patterson


Aertsen, A. M. J. H. and P. I. M. Johannesma (1980). Spectro-temporal receptive fields of auditory neurons in the grassfrog. I. Characterisation of tonal and natural stimuli. Biol. Cybern., 38, 223-234.

Patterson, R.D., Robinson, K., Holdsworth, J., McKeown, D., Zhang, C. and Allerhand M. (1992) 'Complex sounds and auditory images', In: Auditory physiology and perception, Proceedings of the 9h International Symposium on Hearing, Y Cazals, L. Demany, K. Horner (eds), Pergamon, Oxford, 429-446.

Here is a link to the paper:

For those who might be interested, the section of the ISH paper introducing the gammatone auditory filterbank reads as follows:

Spectral Analysis. The gammatone filter is defined in the time domain by its impulse response.


gt(t) = a t(n-1) exp(-2pbt) cos(2p fct + Ã) (t>0) (1)


It was introduced by Aertsen and Johannesma (1980) and used by de Boer and de Jongh (1978) to

characterise 'revcor' data from cats. The primary parameters of the filter are b and n: b largely

etermines the duration of the impulse response and thus,the bandwidth of the filter; n is the order of

the filter and it largely determines the slope of the skirts. When the order of the filter is in the range

3-5, the shape of the magnitude characteristic of the gammatone filter is very similar to that of the

roex(p) filter commonly used to represent the magnitude characteristic of the human auditory filter

(Patterson and Moore, 1986). Glasberg and Moore (1990) have recently summarised human data on

the Equivalent Rectangular Bandwidth (ERB) of the auditory filter with the equation:


ERB = 24.7(4.37fc/1000 + 1) (2)


This function is essentially the same as the 'cochlear frequency position' function that Greenwood

(1990) suggests is the physiological basis for the 'critical band' function. Together Equations 1 and 2

define a gammatone auditory filterbank if one includes the common assumption that the filter centre

frequencies are distributed across frequency in proportion to their bandwidth. When fc/b is large, as

it is in the auditory case, the bandwidth of the filter is proportional to b, and the proportionality

constant only depends on the filter order, n. When the order is 4, b is 1.019 ERB. The 3-dB

bandwidth of the gammatone filter is 0.887 times the ERB (Patterson, Holdsworth, Nimmo-Smith

and Rice, 1988).

Roy Patterson
Centre for the Neural Basis of Hearing
Department of Physiology, Development and Neuroscience
University of Cambridge, Downing Street, Cambridge, CB2 3EG
  phone   +44 (0) 1223 333819    fax 333840
  email:    rdp1@xxxxxxxxx