You could use it if you had another one with a female headphone jack. You could play your music to a speaker in another room if you have Ethernet in both rooms. Copper is copper.
While, as you said, both wires will conduct electricity just fine, they will have different AC impedance.
I would guess this wouldn’t make much of a difference if you go Audio->Ethernet->Audio, since sound is at fairly low frequencies. But Ethernet->Audio->Ethernet might have problems with really high data rates, like GiB/s.
You could use it if you had another one with a female headphone jack. You could play your music to a speaker in another room if you have Ethernet in both rooms. Copper is copper.
While, as you said, both wires will conduct electricity just fine, they will have different AC impedance.
I would guess this wouldn’t make much of a difference if you go Audio->Ethernet->Audio, since sound is at fairly low frequencies. But Ethernet->Audio->Ethernet might have problems with really high data rates, like GiB/s.