Mercurial > hg > camir-aes2014
view toolboxes/MIRtoolbox1.3.2/AuditoryToolbox/MakeVowel.m @ 0:e9a9cd732c1e tip
first hg version after svn
author | wolffd |
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date | Tue, 10 Feb 2015 15:05:51 +0000 |
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function y=MakeVowel(len, pitch, sampleRate, f1, f2, f3) % MakeVowel(len, pitch [, sampleRate, f1, f2, f3]) - Make a vowel with % "len" samples and the given pitch. The sample rate defaults to % be 22254.545454 Hz (the native Mactinosh Sampling Rate). The % formant frequencies are f1, f2 & f3. Some common vowels are % Vowel f1 f2 f3 % /a/ 730 1090 2440 % /i/ 270 2290 3010 % /u/ 300 870 2240 % % The pitch variable can either be a scalar indicating the actual % pitch frequency, or an array of impulse locations. Using an % array of impulses allows this routine to compute vowels with % varying pitch. % % Alternatively, f1 can be replaced with one of the following strings % 'a', 'i', 'u' and the appropriate formant frequencies are % automatically selected. % Modified by R. Duda, 3/13/94 % (c) 1998 Interval Research Corporation if nargin < 2, fprintf('Format: y = MakeVowel(len, pitch [, sampleRate, f1, f2, f3])\n'); return; end; if nargin < 6; f3 = 0; end; if nargin < 5; f2 = 0; end; if nargin < 4, f1 = 0; else if isstr(f1) if f1 == 'a' | f1 == '/a/' f1=730; f2=1090; f3=2440; elseif f1 == 'i' | f1 == '/i/' f1=270; f2=2290; f3=3010; elseif f1 == 'u' | f1 == '/u/' f1=300; f2=870; f3=2240; end end; end; if nargin < 3, sampleRate = 22254.545454; elseif sampleRate < 1000, % Apparently for test purposes sampleRate = 22254.545454; end; % GlottalPulses(pitch, fs, len) - Generate a stream of % glottal pulses with the given pitch (in Hz) and sampling % frequency (sampleRate). A vector of the requested length is returned. y=zeros(1,len); if length(pitch) > 1, % If true, use to determine points points=pitch; % Check for valid sequence of points if any(points~=sort(points)), error('Values in pitch array must be in ascending order.') end; if points(1) < 1, error('Values in pitch array cannot be less than 1.'); end; kmax=sum(points <= len); if kmax == 0, error('All values in pitch array exceed "len"; none should.'); elseif kmax < length(points), fprintf('Some values in pitch array exceed "len"; truncating.\n'); points=points(1:kmax); end; else points=1:sampleRate/pitch:len; end; indices=floor(points); % Use a triangular approximation to an impulse function. The important % part is to keep the total amplitude the same. y(indices) = (indices+1)-points; y(indices+1) = points-indices; % GlottalFilter(x,fs) - Filter an impulse train and simulate the glottal % transfer function. The sampling interval (sampleRate) is given in Hz. % The filtering performed by this function is two first-order filters % at 250Hz. a = exp(-250*2*pi/sampleRate); %y=filter([1,0,-1],[1,-2*a,a*a],y); % Not as good as one below.... y=filter([1],[1,0,-a*a],y); % FormantFilter(input, f, fs) - Filter an input sequence to model one % formant in a speech signal. The formant frequency (in Hz) is given % by f and the bandwidth of the formant is a constant 50Hz. The % sampling frequency in Hz is given by fs. if f1 > 0 cft = f1/sampleRate; bw = 50; q = f1/bw; rho = exp(-pi * cft / q); theta = 2 * pi * cft * sqrt(1-1/(4 * q*q)); a2 = -2*rho*cos(theta); a3 = rho*rho; y=filter([1+a2+a3],[1,a2,a3],y); end; % FormantFilter(input, f, fs) - Filter an input sequence to model one % formant in a speech signal. The formant frequency (in Hz) is given % by f and the bandwidth of the formant is a constant 50Hz. The % sampling frequency in Hz is given by fs. if f2 > 0 cft = f2/sampleRate; bw = 50; q = f2/bw; rho = exp(-pi * cft / q); theta = 2 * pi * cft * sqrt(1-1/(4 * q*q)); a2 = -2*rho*cos(theta); a3 = rho*rho; y=filter([1+a2+a3],[1,a2,a3],y); end; % FormantFilter(input, f, fs) - Filter an input sequence to model one % formant in a speech signal. The formant frequency (in Hz) is given % by f and the bandwidth of the formant is a constant 50Hz. The % sampling frequency in Hz is given by fs. if f3 > 0 cft = f3/sampleRate; bw = 50; q = f3/bw; rho = exp(-pi * cft / q); theta = 2 * pi * cft * sqrt(1-1/(4 * q*q)); a2 = -2*rho*cos(theta); a3 = rho*rho; y=filter([1+a2+a3],[1,a2,a3],y); end;