dicklyon@456: % Copyright 2012, Google, Inc.
dicklyon@456: % Author: Richard F. Lyon
dicklyon@456: %
dicklyon@456: % This Matlab file is part of an implementation of Lyon's cochlear model:
dicklyon@456: % "Cascade of Asymmetric Resonators with Fast-Acting Compression"
dicklyon@456: % to supplement Lyon's upcoming book "Human and Machine Hearing"
dicklyon@456: %
dicklyon@456: % Licensed under the Apache License, Version 2.0 (the "License");
dicklyon@456: % you may not use this file except in compliance with the License.
dicklyon@456: % You may obtain a copy of the License at
dicklyon@456: %
dicklyon@456: %     http://www.apache.org/licenses/LICENSE-2.0
dicklyon@456: %
dicklyon@456: % Unless required by applicable law or agreed to in writing, software
dicklyon@456: % distributed under the License is distributed on an "AS IS" BASIS,
dicklyon@456: % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
dicklyon@456: % See the License for the specific language governing permissions and
dicklyon@456: % limitations under the License.
dicklyon@456: 
tom@455: function ERB = ERB_Hz(CF_Hz, ERB_break_freq, ERB_Q)
tom@455: % function ERB = ERB_Hz(CF_Hz, ERB_break_freq, ERB_Q)
tom@455: %
tom@455: % Auditory filter nominal Equivalent Rectangular Bandwidth
tom@455: %	Ref: Glasberg and Moore: Hearing Research, 47 (1990), 103-138
tom@455: % ERB = 24.7 * (1 + 4.37 * CF_Hz / 1000);
tom@455: 
tom@455: if nargin < 3
tom@455:   ERB_Q = 1000/(24.7*4.37);  % 9.2645
tom@455:   if nargin < 2
tom@455:     ERB_break_freq = 1000/4.37;  % 228.833
tom@455:   end
tom@455: end
tom@455: 
tom@455: ERB = (ERB_break_freq + CF_Hz) / ERB_Q;