Kol Not-Ishah

There is an article in The Jerusalem Post about a 20-year old yeshiva student in Israel whose singing voice sounds like a female's. Because of this, his songs have been banned by certain Haredi radio stations (link).

There is a general halakhah that a man may not hear a woman sing (see here: I, II, III). However, there is a debate regarding hearing a woman's recorded voice. On the one hand, one is not technically hearing a woman's voice but an electronic duplication and amplification of it. Therefore, it should be permissible to hear a woman singing over the radio, on television and even through a microphone (cf. Tzitz Eliezer 5:2:5). On the other hand, if the reason for the prohibition is that it might cause a man to have improper thoughts about the woman, then even a recording might be prohibited. Some limit this to occasions when the man knows what the female singer looks like (cf. Yabi'a Omer 1:Orach Chaim:6).

To some extent, the issue revolves around the reason behind the rule -- is it that a woman's singing voice is inherently prohibited or that hearing it might cause a man to have improper thoughts. If it is the former, then there is ample to room to be lenient because one is not technically hearing a woman's voice. If it is the latter, then there is room to be strict because an electronic replication of a woman's voice sounds the same as the real thing.

What if a man thinks he is hearing a woman's singing voice but really is not? This might be my own limitations but I can't see either side of the debate prohibiting it. The bottom line is that it is not a woman's voice. However, if a man has improper thoughts because of hearing the voice, then he should refrain from listening to it. This can be compared to watching an animated video of a woman improperly dressed (e.g. the Disney version of Aladdin). One is looking at a drawing and not a real woman. However, if a man has improper thoughts from looking at such a drawing then one is forbidden from watching it (heard in the name of R. Hershel Schachter). And, from what I understand, there are animated movies that are far less innocuous than Aladdin that are certainly forbidden.

I presume, perhaps incorrectly, that the same should apply to a man's singing voice that sounds like a woman's (and, according to one opinion above, an electronic transmition of a woman's singing voice). If a listener has improper thoughts then he is obligated to refrain from listening to it.

UPDATED: And what if a woman has a "sexual reassignment" operation or takes steroids and dresses like a man to the point of being unrecognizable as a woman, is it forbidden to listen to her sing? When I had such an issue (believe it or not), I thought that it would revolve around the above discussion. If the prohibition is based on a man having improper thoughts, then hearing such a woman would be permissible. But if it is based on a woman's singing voice being prohibited, then it would be forbidden. I asked someone in kollel, more to freak him out than any other reason, and he said that he thought it would be forbidden no matter what. Then I asked a talmid chakham and he said that he thought it would be permitted according to both views (I didn't have time to find out his reasoning). When I was faced with the case, I left the room as soon as I realized what was going on. But as I was leaving, I heard the voice and it sounded entirely like a man.

(As always, ask a competent rabbi before following anything you read on the internet.)