1.代码
%加载一个蓝鲸音频数据的文件,信号中有两种声音。一种是颤音，另一种是呻吟声。
clear;
clc;
[y,fs]=audioread('bluewhale.wav');
%sound(y,fs); %听音频
whale=timetable(y,'SampleRate',fs);
figure(1)
stackedplot(whale);
%HHT
imf=emd(whale,'MaxNumIMF',3,'Display',1);
%Use the computed IMFs to plot the Hilbert spectrum of the signal. Restrict the frequency range
%from 0 Hz to 1400 Hz.
figure(2)
hht(imf,'FrequencyLimits',[0 1400])
figure(3)
[hs,f,t] = hht(imf,'FrequencyLimits',[0 1400]);
mesh(seconds(t),f,hs,'EdgeColor','none','FaceColor','interp')
xlabel('Time (s)')
ylabel('Frequency (Hz)')
zlabel('Instantaneous Energy')2.运行结果
