基于MATLAB实现传统谱减法以及两种改进的谱减法（增益函数谱减法、多带谱减法）的语音增强代码示例：

传统谱减法

function enhanced = traditional_spectral_subtraction(noisy, fs, wlen, inc, NIS, a, b)% 参数说明：% noisy - 带噪语音信号% fs - 采样频率% wlen - 帧长% inc - 帧移% NIS - 前导无话段帧数% a - 过减因子% b - 增益补偿因子% 计算噪声功率谱noise_frames = buffer(noisy(1:NIS*inc), wlen, wlen-inc);noise_frames = noise_frames(:, 1:NIS);noise_power = mean(abs(fft(noise_frames)).^2, 2);% 分帧frames = buffer(noisy, wlen, wlen-inc);num_frames = size(frames, 2);% 初始化增强后的语音enhanced = zeros(size(noisy));% 谱减法处理for i = 1:num_frames% FFTX = fft(frames(:, i));X_mag = abs(X);X_phase = angle(X);% 谱减法S_mag = max(X_mag - a * sqrt(noise_power), b * sqrt(noise_power));% 逆FFTS = S_mag .* exp(1j * X_phase);enhanced_frame = real(ifft(S));% 重叠相加enhanced((i-1)*inc+1:(i-1)*inc+wlen) = enhanced((i-1)*inc+1:(i-1)*inc+wlen) + enhanced_frame;end
end

增益函数谱减法

function enhanced = gain_function_spectral_subtraction(noisy, fs, wlen, inc, NIS, alpha, beta)% 参数说明：% noisy - 带噪语音信号% fs - 采样频率% wlen - 帧长% inc - 帧移% NIS - 前导无话段帧数% alpha - 过减因子% beta - 增益补偿因子% 计算噪声功率谱noise_frames = buffer(noisy(1:NIS*inc), wlen, wlen-inc);noise_frames = noise_frames(:, 1:NIS);noise_power = mean(abs(fft(noise_frames)).^2, 2);% 分帧frames = buffer(noisy, wlen, wlen-inc);num_frames = size(frames, 2);% 初始化增强后的语音enhanced = zeros(size(noisy));% 谱减法处理for i = 1:num_frames% FFTX = fft(frames(:, i));X_mag = abs(X);X_phase = angle(X);% 增益函数G = (X_mag - alpha * sqrt(noise_power)) ./ X_mag;G = max(G, beta);% 增强后的频谱S_mag = G .* X_mag;% 逆FFTS = S_mag .* exp(1j * X_phase);enhanced_frame = real(ifft(S));% 重叠相加enhanced((i-1)*inc+1:(i-1)*inc+wlen) = enhanced((i-1)*inc+1:(i-1)*inc+wlen) + enhanced_frame;end
end

多带谱减法

function enhanced = multiband_spectral_subtraction(noisy, fs, wlen, inc, NIS, num_bands)% 参数说明：% noisy - 带噪语音信号% fs - 采样频率% wlen - 帧长% inc - 帧移% NIS - 前导无话段帧数% num_bands - 子带数量% 计算噪声功率谱noise_frames = buffer(noisy(1:NIS*inc), wlen, wlen-inc);noise_frames = noise_frames(:, 1:NIS);noise_power = mean(abs(fft(noise_frames)).^2, 2);% 分帧frames = buffer(noisy, wlen, wlen-inc);num_frames = size(frames, 2);% 初始化增强后的语音enhanced = zeros(size(noisy));% 子带划分band_width = wlen / num_bands;% 谱减法处理for i = 1:num_frames% FFTX = fft(frames(:, i));X_mag = abs(X);X_phase = angle(X);% 多带谱减法S_mag = zeros(size(X_mag));for j = 1:num_bandsband_start = (j-1) * band_width + 1;band_end = j * band_width;band_noise_power = noise_power(band_start:band_end);S_mag(band_start:band_end) = max(X_mag(band_start:band_end) - band_noise_power, 0);end% 逆FFTS = S_mag .* exp(1j * X_phase);enhanced_frame = real(ifft(S));% 重叠相加enhanced((i-1)*inc+1:(i-1)*inc+wlen) = enhanced((i-1)*inc+1:(i-1)*inc+wlen) + enhanced_frame;end
end

使用示例

% 读取带噪语音信号
[noisy, fs] = audioread('noisy_speech.wav');% 参数设置
wlen = 256; % 帧长
inc = 128; % 帧移
NIS = 10; % 前导无话段帧数
a = 4; % 过减因子
b = 0.001; % 增益补偿因子
alpha = 4; % 增益函数过减因子
beta = 0.001; % 增益函数增益补偿因子
num_bands = 4; % 多带谱减法子带数量% 传统谱减法
enhanced_traditional = traditional_spectral_subtraction(noisy, fs, wlen, inc, NIS, a, b);% 增益函数谱减法
enhanced_gain_function = gain_function_spectral_subtraction(noisy, fs, wlen, inc, NIS, alpha, beta);% 多带谱减法
enhanced_multiband = multiband_spectral_subtraction(noisy, fs, wlen, inc, NIS, num_bands);% 保存增强后的语音
audiowrite('enhanced_traditional.wav', enhanced_traditional, fs);
audiowrite('enhanced_gain_function.wav', enhanced_gain_function, fs);
audiowrite('enhanced_multiband.wav', enhanced_multiband, fs);