What should a girl do who has a beautiful voice, which some describe as "seductive"; should she refrain from answering calls?

You must refrain from answering the phone to prevent temptation and to cut off the devil’s footsteps, for Allah Almighty says: (O you who have believed, do not follow the footsteps of Satan. And whoever follows the footsteps of Satan - indeed, he enjoins immorality and wrongdoing). And for a woman whose voice might cause temptation, it is obligatory upon her not to let strangers hear her voice except in cases of dire necessity, for Allah Almighty says: (So do not be soft in speech [to men], lest he in whose heart is disease should covet, but speak with appropriate speech).