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From these charts we can understand why AM is considered the band for talk programming.
Probably this perception is related to the point that an audio bandwidth of 5 kHz or so includes the more important spectral components of human voices.
In practical terms it is also related to the fact that the FCC allocation plan for AM broadcast stations does not provide r-f channels permitting ~ interference-free audio bandwidths greater than 5 kHz for analog AM broadcast stations — particularly at night when strong skywave signals may be present on adjacent channels.
For this reason (interference), the manufacturers of most consumer-level AM broadcast receivers have restricted their r-f and a-f bandwidths so as to minimize such interference, meaning that they have little audio output above 4 to 5 kHz.
However this does not mean that AM as a process is incapable of transmitting baseband frequencies much higher than 5 kHz, or that AM receivers cannot detect baseband modulating frequencies above 5 kHz.
For a common example of this, analog NTSC TV transmitters used AM to transmit video baseband frequencies extending from about 60 Hz to about 4 MHz.
TV receivers using that standard had no problem receiving and displaying that bandwidth, because the FCC allocation plan for those TV stations was designed to permit it.