Matlab-如何使用頻譜圖函數？

Question

我通過[data，fs，bit] = wavread（'*。wav'）;加載了wav文件； 我想使用specgram函數可視化此wav文件。

像這樣！

讓我知道如何像這樣顯示可視化的wav文件。 （我想分析wav文件聲音的頻率）

Answer 1

唉...我不給陰謀例如，作為Matlab的specgram和spectrogram ，但我會給另一種方式來做到這一點。

首先，您要使用FFT將時域信號轉換為短時頻域（STFT）：

這可以通過matlab specgram完成：

[data,fs,bit] = wavread('test.wav'); %//Read in WAV file
%//Note if you have dual channel or multi-channel, you need to do each channel separately, or add them to create mono-channel. In my example, which is voice, I use a single channel recording.
teststft = spectrogram(data); %//This is rough, and usually results in terrible results;
%//I suggest you set your input parameters suitable for voice/music/etc - Note I used hamming window of 256 length, 50% overlap and 512 nfft - which creates roughly 30ms time frames, suitable for voice.

teststft = spectrogram(data(:,1),hamming(256),50,512);

%//In your plotting example, you have used something like the Log Magnitude response, which can be expressed as:
testSTFT = log(abs(teststft));

%//and finally, to plot:

figure
surf(STFT, 'edgecolor', 'none'); view(0,90); axis tight;
xlabel('Time');
ylabel('FrequencyDistribution');
grid on;

結果看起來像：