“MDG: That’s not an Issur of Kol Isha, that’s an Issur of looking/interacting with a woman in any way for inappropriate enjoyment. Afilu Etzbah K’tanah… “
IMHO, inappropriate enjoyment of the voice is called Kol Isha.
Anyways, I was quoting the Magid Shiur that I learned it from. For the sake of anonymity, I’m not saying who it was.