I used an online tuning fork to generate a tone and then listened to it while recording myself singing back the same note. [At this point I realised my voice was very "pitchy" as playing my voice together with the tone resulting in a discordant sound where the two pitches varied ever so slightly, so when conducting this experiment some degree of inaccuracy should be expected....]
In Audacity, go to Analyze > Plot Spectrum...
Increase the size to 16384 (maximum)
Set Axis to Log (Logarithmic) to see the notes and frequencies present (The "highest" point means that frequency is loudest in that recording).
Frequency Spectrum of myself singing 329.63Hz (E)
Result: Peak Spectrum of 330Hz (E)
Frequency Spectrum of myself singing 220Hz (A)
Result: Peak Spectrum of 219Hz