function [output,time] = Wiener(signal,fs,type,IS)

if (nargin<4 || isstruct(IS))

    IS=.25; %Initial Silence or Noise Only part in seconds

end

W=fix(.025*fs); %Window length is 25 ms

SP=.4; %Shift percentage is 40% (10ms) %Overlap-Add method works good with this value(.4)

wnd=hann(W);

pre_emph=0;

signal=filter([1 -pre_emph],1,signal);

NIS=fix((IS*fs-W)/(SP*W) +1);%number of initial silence segments

y=segment(signal,W,SP,wnd); % This function chops the signal into frames

Y=fft(y);

YPhase=angle(Y(1:fix(end/2)+1,:)); %Noisy Speech Phase

Y=abs(Y(1:fix(end/2)+1,:));%Specrogram

numberOfFrames=size(Y,2);

FreqResol=size(Y,1);

N=mean(Y(:,1:NIS)')'; %initial Noise Power Spectrum mean

LambdaD=mean((Y(:,1:NIS)').^2)';%initial Noise Power Spectrum variance

alpha=.99; %used in smoothing xi (For Deciesion Directed method for estimation of A Priori SNR)

NoiseCounter=0;

NoiseLength=9;%This is a smoothing factor for the noise updating

G=ones(size(N));%Initial Gain used in calculation of the new xi

Gamma=G;

X=zeros(size(Y)); % Initialize X (memory allocation)

h=waitbar(0,'Wait...');

for i=1:numberOfFrames

    %%%%%%%%%%%%%%%%VAD and Noise Estimation START

    if i<=NIS % If initial silence ignore VAD

        SpeechFlag=0;

        NoiseCounter=100;

    else % Else Do VAD

        [NoiseFlag, SpeechFlag, NoiseCounter, Dist]=vad(Y(:,i),N,NoiseCounter); %Magnitude Spectrum Distance VAD

    end

    if SpeechFlag==0 % If not Speech Update Noise Parameters

        N=(NoiseLength*N+Y(:,i))/(NoiseLength+1); %Update and smooth noise mean

        LambdaD=(NoiseLength*LambdaD+(Y(:,i).^2))./(1+NoiseLength); %Update and smooth noise variance

    end

    %%%%%%%%%%%%%%%%%%%VAD and Noise Estimation END

    gammaNew=(Y(:,i).^2)./LambdaD; %A postiriori SNR

    xi=alpha*(G.^2).*Gamma+(1-alpha).*max(gammaNew-1,0); %Decision Directed Method for A Priori SNR

    Gamma=gammaNew;

    G=(xi./(xi+1));

    X(:,i)=G.*Y(:,i); %Obtain the new Cleaned value

    waitbar(i/numberOfFrames,h,num2str(fix(100*i/numberOfFrames)));

end

close(h);

output = OverlapAdd2(X,YPhase,W,SP*W); %Overlap-add Synthesis of speech

output = filter(1,[1 -pre_emph],output); %Undo the effect of Pre-emphasis

num = [0.00247553277809987,0.00495106555619995,0.00247553277809975];

den = [1,-1.80098109524571,0.810883226358106];

output = filter(num,den,output);

time = (0:1/fs:(size(output,1)-1)/fs);

if type == 1

    output = 100.*output;

end

function ReconstructedSignal=OverlapAdd2(XNEW,yphase,windowLen,ShiftLen)

if nargin<2

    yphase=angle(XNEW);

end

if nargin<3

    windowLen=size(XNEW,1)*2;

end

if nargin<4

    ShiftLen=windowLen/2;

end

if fix(ShiftLen)~=ShiftLen

    ShiftLen=fix(ShiftLen);

    disp('The shift length have to be an integer as it is the number of samples.')

    disp(['shift length is fixed to ' num2str(ShiftLen)])

end

[FreqRes, FrameNum]=size(XNEW);

Spec=XNEW.*exp(1i*yphase);

if mod(windowLen,2) %if FreqResol is odd

    Spec=[Spec;flipud(conj(Spec(2:end,:)))];

else

    Spec=[Spec;flipud(conj(Spec(2:end-1,:)))];

end

sig=zeros((FrameNum-1)*ShiftLen+windowLen,1);

weight=sig;

for i=1:FrameNum

    start=(i-1)*ShiftLen+1;    

    spec=Spec(:,i);

    sig(start:start+windowLen-1)=sig(start:start+windowLen-1)+real(ifft(spec,windowLen));    

end

ReconstructedSignal=sig;

function Seg=segment(signal,W,SP,Window)

if nargin<3

    SP=.4;

end

if nargin<2

    W=256;

end

if nargin<4

    Window=hamming(W);

end

Window=Window(:); %make it a column vector

L=length(signal);

SP=fix(W.*SP);

N=fix((L-W)/SP +1); %number of segments

Index=(repmat(1:W,N,1)+repmat((0:(N-1))'*SP,1,W))';

hw=repmat(Window,1,N);

Seg=signal(Index).*hw;

function [NoiseFlag, SpeechFlag, NoiseCounter, Dist]=vad(signal,noise,NoiseCounter,NoiseMargin,Hangover)

if nargin<4

    NoiseMargin=3;

end

if nargin<5

    Hangover=8;

end

if nargin<3

    NoiseCounter=0;

end

FreqResol=length(signal);

SpectralDist= 20*(log10(signal)-log10(noise));

SpectralDist(SpectralDist<0)=0;

Dist=mean(SpectralDist); 

if (Dist < NoiseMargin) 

    NoiseFlag=1; 

    NoiseCounter=NoiseCounter+1;

else

    NoiseFlag=0;

    NoiseCounter=0;

end

% Detect noise only periods and attenuate the signal     

if (NoiseCounter > Hangover) 

    SpeechFlag=0;    

else 

    SpeechFlag=1; 

end