xnneframe.m

这是一个用于语音信号处理的工具箱

function [NE, SE, M]=xNNEframe(speechframe, Tp)

% Input
% 	speechframe : A frame of speech signal to be analyzed
%	Tp : pitch period of the input frame 
% Output
%	NE : energy of the noise in the frequency range
%	     from approximately 1 kHz to 5 kHz
%	SE : energy of the signal in the same frequency range
%

N=2048;
len=length(speechframe);
wframe=speechframe.*hamming(len);
pad=zeros(N,1);
pad(1:len)=wframe;
X=fft(pad,N);
X=X.*conj(X);
X=X(1:N/2);

f=N/Tp;
lobe=round(2*N/M);

i=1;
a=round(0.8*f);
low=a;
b=round(1.3*f);

while b < 0.9*N/2
	[p,ploc]=max(X(a:b));
	ploc=ploc+a-1;
	
	if last -b <= lobe
		break;
	else
		peaklocs(i)=ploc;
		i=i+1;
		c=round(f*i)+1;
		a=round(f+ploc)-lobe;
		b=a+2*lobe;
	end
end

ifirst=round(1000*N/(Fs*f));
first=peaklocs(ifirst)+lobe+1;
ilast=i-1;
last=peaklocs(ilast)-lobe;

if min(diff(peaklocs(ifirst:ilast)))-2*lobe < 1
	M=4*N/(2*eps+min(diff(peaklocs(ifirst:ilast)))-2);
	NE=0;
	SE=0;
else
	a=first;
	b=peaklocs(ifirst+1)-lobe;
	NE=sum(X(a:b));
	meanNE=mean(X(a:b));
	begin=ifirst+1;
	for i=begin:ilast-1
		a=peaklocs(i)-lobe+1;
		b=peaklocs(i+1)-lobe;
		dipwidth=b-a+1;
		m=mean(X(a:b));
		NE=NE+m*dipwidth+lobe*(meanNE+m);
		meanNE=m;
	end
end
SE=sum(X(first:last));