 If  signals are close but not exactly on the same frequency, the  mix will not only have the audio from both carriers, but depending on the carrier separation also include an audible heterodyne "beat note" tone equal to the difference between the carrier frequencies.
<clarity>  If  signals are close but not exactly on the same frequency, the  mix will not only have the audio from both carriers, but depending on the carrier separation also include an audible heterodyne "beat note" tone equal to the difference between the carrier frequencies.
 If signals are close but not exactly on the same frequency, the mix will not only have the audio from both carriers, but depending on the carrier separation will include an audible heterodyne "beat note" tone equal to the difference between the carrier frequencies.