How to find crackles symptoms in lung recorded signal (find signal in other signal)

Hi , i've recorded lung sound using electret microphone. the signal is filtered and clean enough. i have to determine if another signal exist in the recorded signal.

the other signal look like :

the specs of this signal is : IDW : >= 1.5 mS 2CD : >= 10 mS

I dont have any idea where to start .

Thank you in advance.