1. Introduction
Speech enhancement based on matlab iir band stop filter
Second, the source code
%% P2_2_1 语音信号采样，画出时域和频域的图
[y,fs] = audioread('myname.wav');% y为采样数据；fs为采样频率
sound(y,fs); % 播放语言信号myname
N = length(y); % 信号的长度
t = (0:N-1)/fs; % 时域范围
figure(1);subplot(211);plot(t,y); title('音频时域图');%音频信号时域图
xlabel('Time');ylabel('Amplitude');
Y = fft(y,N); % FFT分析频谱
df = fs/length(Y); % 计算谱线间隔
f = 0:df:(fs/2-df); % 频谱范围，截取前半段（抽样频率高于最大频率的2倍）
Yf = abs(Y); % 幅度响应
Yf = Yf(1:length(Yf)/2);% 由于幅度响应是偶函数，所以截取一半
% 画图
figure(1);
subplot(212);axis([0,fs/5,0,5000]);plot(f,Yf);title('音频频谱图');
%% P2_2_2 加入噪声之后的时域和频域图
y = y(:,1); y = y';
nt = randn(1,length(y)); % 生成高斯噪声
%设计BPF得到4KHZ到5KHZ的噪音
fp1 = 4000;fp2 = 5000; % BPF指标
WP1 = 2*pi*fp1/fs;WP2 = 2*pi*fp2/fs;% 将模拟指标转换为数字指标
wn1 = [WP1 WP2];
b = fir1(34,wn1,'bandpass');
yn = filter(b,1,nt); % 噪声的信号
s = y+yn; % 将带限噪音和原来的音频混合
%sound(s,fs);
S = fft(s,N);
Sf = abs(S); % 幅度
DF = fs/length(S); % 计算谱线间隔
f = 0:DF:(fs/2-DF); % 频谱范围，截取前半段（抽样频率高于最大频率的2倍）
Sf = Sf(1:length(Sf)/2); % 由于幅度响应是偶函数，所以截取一半
% 画图
figure(2);
subplot(211);plot(t,s); title('加入噪声的音频时域图');
xlabel('Time');ylabel('Amplitude');grid on;
subplot(212);axis([0,fs/5,0,10000]);plot(f,Sf);title('加入噪声的音频频谱图');
xlabel('Frequency');ylabel('Amplitude');grid on;
%% P2_2_3 设计滤波器,并滤波
%设计带阻滤波器滤除噪声
FP1 = 3500;FS1 = 3600;FP2 = 5600;FS2 = 5500;
rp2 = 1;rs2 = 40;
FP = [FP1 FP2];FS = [FS1 FS2];
wp = 2*pi*FP/fs; % 将模拟指标转换为数字指标
ws = 2*pi*FS/fs; % 用切比雪夫IIR滤波器
[n,wn] = cheb1ord(wp,ws,rp2,rs2); % 滤波器的最小阶数为n，wn为系统频带
[bz,az] = cheby1(n,rp2,wp,'stop');
sound(yfilt,fs); % 播放滤波后的语音信号
Yfil = abs(fft(yfilt,N));
Yf = Yfil(1:length(Yfil)/2);
Three, running results
Four, remarks
Complete code or writing add QQ 1564658423 past review
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[Feature extraction] Audio watermark embedding and extraction based on matlab wavelet transform [Include Matlab source code 053]
[Speech processing] Voice signal processing based on matlab GUI [Include Matlab Source code issue 290]
[Voice acquisition] based on matlab GUI voice signal collection [including Matlab source code 291]
[Voice modulation] based on matlab GUI voice amplitude modulation [including Matlab source code 292]
[Speech synthesis] based on matlab GUI voice synthesis [including Matlab Source code issue 293]
[Voice encryption] Voice signal encryption and decryption based on matlab GUI [With Matlab source code 295]
[Speech enhancement] Matlab wavelet transform-based voice enhancement [Matlab source code 296]
[Voice recognition] Based on matlab GUI voice base frequency Recognition [Including Matlab source code 294]
[Speech enhancement] Matlab GUI Wiener filtering based voice enhancement [Including Matlab source code 298]
[Speech processing] Based on matlab GUI voice signal processing [Including Matlab source code 299]
[Signal processing] Based on Matlab speech signal spectrum analyzer [including Matlab source code 325]
[Modulation signal] Digital modulation signal simulation based on matlab GUI [including Matlab source code 336]
[Emotion recognition] Voice emotion recognition based on matlab BP neural network [including Matlab source code 349 Issue]
[Voice Steganography] Quantified Audio Digital Watermarking Based on Matlab Wavelet Transform [Include Matlab Source Code Issue 351]
[Feature extraction] based on matlab audio watermark embedding and extraction [including Matlab source code 350 period]
[speech denoising] based on matlab low pass and adaptive filter denoising [including Matlab source code 352 period]
[emotion recognition] based on matlab GUI voice emotion classification Recognition [Including Matlab source code 354 period]
[Basic processing] Matlab-based speech signal preprocessing [Including Matlab source code 364 period]
[Speech recognition] Matlab Fourier transform 0-9 digital speech recognition [Including Matlab source code 384 period]
[Speech Recognition] 0-9 digital speech recognition based on matlab GUI DTW [including Matlab source code 385]
[Voice playback] Matlab GUI MP3 design [including Matlab source code 425]
[Voice processing] Speech enhancement algorithm based on human ear masking effect Noise ratio calculation [Including Matlab source code 428]
[Speech denoising] Based on matlab spectral subtraction denoising [Including Matlab source code 429]
[Speech recognition] BP neural network speech recognition based on the momentum item of matlab [Including Matlab source code 430]
[Voice steganography] based on matlab LSB voice hiding [including Matlab source code 431]
[Voice recognition] based on matlab male and female voice recognition [including Matlab source code 452]
[Voice processing] based on matlab voice noise adding and noise reduction processing [including Matlab source code Issue 473]
[Speech denoising] based on matlab least squares (LMS) adaptive filter [including Matlab source code 481]
[Speech enhancement] based on matlab spectral subtraction, least mean square and Wiener filter speech enhancement [including Matlab source code 482 period】
[Communication] based on matlab GUI digital frequency band (ASK, PSK, QAM) modulation simulation [including Matlab source code 483]
[Signal processing] based on matlab ECG signal processing [including Matlab source code 484]
[Voice broadcast] based on matlab voice Broadcast [Including Matlab source code 507]
[Signal processing] Matlab wavelet transform based on EEG signal feature extraction [Including Matlab source code 511]
[Voice processing] Based on matlab GUI dual tone multi-frequency (DTMF) signal detection [Including Matlab source code 512 】
【Voice steganography】based on matlab LSB to realize the digital watermark of speech signal 【Include Matlab source code 513】
【Speech enhancement】Speech recognition based on matlab matched filter 【Include Matlab source code 514】
【Speech processing】Based on matlab GUI voice Frequency domain spectrogram analysis [including Matlab source code 527]
[Speech denoising] based on matlab LMS, RLS algorithm voice denoising [including Matlab source code 528]
[Voice denoising] based on matlab LMS spectral subtraction voice denoising [including Matlab Source code issue 529]
[Voice denoising] based on matlab soft threshold, hard threshold, compromise threshold voice denoising [including Matlab source code 530]
[Voice recognition] based on matlab specific person's voice recognition discrimination [including Matlab source code 534]
[ Speech denoising] based on matlab wavelet soft threshold speech noise reduction [including Matlab source code 531]
[speech denoising] based on matlab wavelet hard threshold speech noise reduction [including Matlab source code 532]
[speech recognition] based on matlab MFCC and SVM specific Human gender recognition [including Matlab source code 533]
[Voice recognition] GMM speech recognition based on MFCC [including Matlab source code 535 period]
[Voice recognition] Based on matlab VQ specific person isolated words voice recognition [including Matlab source code 536 period]
[Voice recognition] based on matlab GUI voiceprint recognition [including Matlab] Source code issue 537]
[Collection and reading] Based on matlab voice collection and reading [including Matlab source code 538]
[Voice editing] based on matlab voice editing [including Matlab source code 539]
[Voice model] based on matlab voice signal mathematical model [including Matlab source code 540]
[Speech soundness] based on matlab voice intensity and loudness [including Matlab source code 541]
[Emotion recognition] based on matlab K nearest neighbor classification algorithm voice emotion recognition [including Matlab source code 542]
[Emotion recognition] based on matlab Support vector machine (SVM) speech emotion recognition [including Matlab source code 543]
[Emotion recognition] Neural network-based speech emotion recognition [including Matlab source code 544]
[Sound source localization] Sound source localization based on matlab different spatial spectrum estimation Algorithm comparison [Include Matlab source code 545]
[Sound source localization] Based on matlab microphone receiving signal under different signal-to-noise ratio [Include Matlab source code 546]
[Sound source localization] Room impulse response based on matlab single sound source and dual microphones [ Contains Matlab source code 547]
[Sound source localization] Matlab generalized cross-correlation sound source location [Matlab source code 548 is included]
[Sound source location] Matlab array manifold matrix-based signal display [Matlab source code 549]
[Features Extraction] based on matlab formant estimation [including Matlab source code 550 period]
[Feature extraction] based on matlab pitch period estimation [including Matlab source code 551]
[Feature extraction] based on matlab voice endpoint detection [including Matlab source code 552]
[Voice coding] based on matlab ADPCM codec [including Matlab source code 553]
[Voice Encoding] based on matlab LPC encoding and decoding [including Matlab source code 554]
[Voice encoding] based on matlab PCM encoding and decoding [including Matlab source code 555]
[Speech analysis] Based on matlab cepstrum analysis and MFCC coefficient calculation [including Matlab source code 556]
[Speech analysis] based on matlab linear prediction coefficient comparison [including Matlab source code 557]
[speech analysis] based on matlab voice short-time frequency domain analysis [including Matlab source code 558]
[speech analysis] based on matlab voice short-time time domain analysis [including Matlab Source code issue 559]
[Speech analysis] based on matlab voice line spectrum pair conversion [including Matlab source code 560]
[speech synthesis] signal framing and restoration based on matlab proportional overlap and addition [including Matlab source code 561]
[Speech synthesis] Speech synthesis based on matlab linear prediction formant detection and pitch parameters [with Matlab source code 562]
[speech synthesis] based on matlab linear prediction coefficients and pitch parameters [with Matlab source code 563]
[speech synthesis] based on matlab linear prediction Coefficient and prediction error speech synthesis [Include Matlab source code 564]
[Speech synthesis] Matlab-based voice signal speed change [Include Matlab source code 565]
[Speech synthesis] Matlab voice signal-based tone change [Include Matlab source code 566]
[Speech synthesis] signal framing and restoration based on matlab overlap storage method [including Matlab source code 567]
[Speech synthesis] signal framing and restoration based on matlab overlap addition method [including Matlab source code 568]
[Voice denoising] Improved spectral subtraction speech denoising based on matlab [including Matlab source code 569]
[Voice denoising] Based on matlab basic Wiener filter algorithm speech denoising [including Matlab source code 570]
[Voice denoising] Based on matlab spectral subtraction voice denoising[ Include Matlab source code 571]
[Speech denoising] Wiener filter algorithm based on Matlab prior SNR [Include Matlab source code 572]
[Speech recognition] Isolated word speech recognition based on matlab dynamic time warping (DTW) [Includes Matlab source code 573]
[Speech recognition] Matlab Gaussian Mixture Model (GMM) based speaker recognition [Includes Matlab source code 574]
[Speech recognition] Matlab vector quantization (VQ) based speaker recognition [Matlab source code 575 included Issue]
[Speech recognition] Isolated word speech recognition based on matlab Hidden Markov Model (HMM) [Include Matlab source code 576]
[Voice hiding] Based on matlab LSB voice information hiding [Include Matlab source code 577]
[Speech recognition] Based on Matlab brainwave sleep monitoring [including Matlab source code 595]
[Voice recognition] based on matlab GUI intelligent voice recognition access control system [including Matlab source code 596]
[Voice recognition] matlab SVM EEG signal staged sleep monitoring [including Matlab source code 611 Issue]
[Speech recognition] Chinese and English species recognition based on combining mfcc and lpc features and SVM classification [including Matlab source code 612 issue]