Listening to Music in the Year of Mourning from a Nearby Banquet Hall

A mourner within the year of his mother's passing lives near a wedding hall and is forced to hear songs from the hall every evening. What should he do?

He should divert his attention and intend not to listen or enjoy the songs. He does not need to plug his ears or reduce his time at home because of this.  

In the Talmud, Pesachim 25b, there is a discussion between Abaye and Rava regarding benefit that comes to a person against his will, whether it is permitted or forbidden. See there for the two opinions. Nevertheless, the law follows Rabbi Shimon that something unintended is permitted, and therefore, certainly, what is impossible and unintended is permitted. Even if it is possible and unintended to enjoy, it is permitted if one can avoid enjoyment. Then it is not considered 'psik reisha'. This is also the ruling of the Rema, Yoreh De'ah, Siman 142, Paragraph 15: "It is forbidden to listen to musical instruments of idol worship or to look at the beauty of idol worship, as one derives pleasure from seeing. However, the Rema wrote that something unintended is permitted." The Shach wrote there, Sif-Katan 34, as follows: "And it is explained there in the Talmud and the decisors that even if it is possible to go elsewhere, it is permitted if one does not intend, and it is explained in Tosafot, the Rosh, and the Riva there that it refers to a situation where one can plug his ears, close his eyes, and block his nostrils so as not to enjoy the sound, sight, and smell, and it is permitted if one does not intend to enjoy, as it is not 'psik reisha', otherwise it is forbidden. But if one intends, it is explained there in the Talmud and the decisors that even if it is impossible to go elsewhere, it is forbidden. Therefore, one does not need to plug his ears, it is enough that he can plug his ears and not hear, and this is no longer 'psik reisha', and it is enough that he does not intend to enjoy. See Chochmat Adam, Klal 84, Paragraph 16. And in Chafetz Chaim, Klal 6, in the note in Be'er Mayim Chaim, Sif-Katan 14.