How do I find the frequency of "hum" in a recording?

Hello,
I have some audio from a camcorder that is marred by a hum from the built-in microphone. It's not 60Hz since removing that made no difference. My question is - what tool would I use in Audition 3.01 to find the frequency (range) of a sound, a hum in this case, so that I can use say a notch filter to remove/minimize it? I tried using the spectral view but that didn't help. Maybe I'm missing the obvious, in which case please be kind to one less learned such as myself:) Any help would be greatly appreciated- thanks everyone!

>Normally hum is caused by a poorly shielded (or unshielded) microphone cable running near a transformer (external brick power supply).
a) There's no such thing as 'normal' where hum is concerned - I could easily give you many possibilities - the scenario you suggest isn't even particularly prevalent.
b) This isn't hum we are talking about here, but harmonic hash, and on top of that, it's in a camcorder. The cause? Quite frankly, all bets are off. As for your explanation of clipping causing the harmonic series - well, I don't know what planet you are living on, but in my
considerable experience of this phenomenon as an ex-mixer designer, I can tell you that this really has very little, if anything at all, to do with it.
If you actually want to know, most hum harmonics generation has more to do with earthing mismatches allowing induced leakage current from power supplies into signal-carrying tracks. In the case of conventional camcorders, it's different though - here you have several sources of interference involved in generating the relatively high levels of signal at the field repetition rate adjacent to the relatively sensitive mic input stages, and with the best will in the world, any linear-based signal recording is going to have a poor S/N ratio, and the noise floor is likely to have a lot of harmonics of 60Hz - because that's pretty much what gets generated within the casing at the highest levels, and it's pervasive. Clipping doesn't even get a look-in in this situation.

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How do I find the frequency of "hum" in a recording?

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