Hi. I am doing a project about the Doppler Effect and I was wondering if someone here could help me. I have a tone source and I need to find the frequency with respect to time. I could use my mp3 player to record this frequency, which will then save it as a .wav file. I was wondering if there was software (free?) that could let me physically view the sound. I have already tried messing around with Nero's Wave Editor, but I am unable to get any relevent information from it. I would like to make a graph of frequency vs time. Any help would be appreciated. Thanks in advance.