https://www.koltorah.org/halachah/the-parameters-of-kol-isha-by-rabbi-chaim-jachter
Rav Yaakov Breisch (Teshuvot Chelkat Yaakov 1:163), on the other hand, forbids a man to listen to a female voice on the radio. He reasons that the aforementioned Gemara in Sanhedrin 45a does not apply when there is some form of connection with the woman. He argues that a man’s Yetzer Hara is interested even if he only hears a woman’s voice. He rules strictly even in case where the listener is not acquainted with the singer. Rav Shmuel Wosner (Teshuvot Shevet Halevi 3:E.H.181 and Rav Binyamin Silber (Az Nidberu 9:9) also rule strictly on this question.
Observance of the Kol Isha prohibition is quite challenging for us as this prohibition runs counter to the prevailing Western culture. In today’s promiscuous society where outrageous behavior is deemed acceptable, a woman’s singing voice appears innocuous. Moreover, the general culture views this prohibition offensive and demeaning to women. We are challenged to hold firm to our beliefs against the flow of the general cultural tide. This is one of the issues that we must part company with the rest of society, just as Avraham Avinu and Yitzchak Avinu parted with their two servants on the road to Akeidat Yitzchak. Rav Yehuda Amital told me that we should strictly observe the Kol Isha prohibition today precisely because of the deterioration of the moral standards of western society.
