?????? ???– Questions and Answers on the Shulchan Aruch.
Siman 104:
Regarding wherever its permitted to hear the voice of your sister singing:
With regard to hearing her whilst saying Kerias Shema, this is defiantly forbidden, as this is explained in Shulchan Aruch, Orach Chaim (Siman 75,63), you should be cautious to hearing the voice of a woman at the time of reading Shema, even his wife. However a voice that he is accustomed to is not ervah (immorality)(see there).
If he is forbidden to hear his wife, all the more so his sister. Even regarding hearing the voice of a woman not when he is saying Kerias Shema, it appears he is forbidden to hear his sister voice. This is explained in Shulchan Aruch Even Ezer, (Siman 21, 61)its forbidden to hear the voice of a ervah or see her hair.
Its written in BASH(Siman 104), but the sound of his wife or a single woman its permitted, and only at the time of prayer is it forbidden (see there).
Theres no more novelty written there because even the voice of his sister is forbidden, and its clear from here that the voice of his sister is forbidden. It is implied from there (Siman 67), if you hug or kiss one of the arayos (forbidden relations) in which the heart of someone doesn’t beat (he is not sexually attracted to her), for example his older sister and his fathers sister and like examples,even if he doesn’t have any benefit at all from them this is a degradation and its a forbidden matter, and its a act of foolishness that he is not related to in ervah (forbiden relation). This is wherever they are old or young, except if he has relations with his fathers daughter and his mothers son (see there), and its explained that his sister is a ervah and the voice is not to do with sexual closeness.
Therefore when it says its is forbidden to hear the voice of a ervah, it includes the sister.
The BASH writes on (114)he brings the TAZ that it is permitted to examine the head of his sister (see there).
In Choshen Misphat (109)it writes that it is permitted to seclude a man with his sister for short periods, and so it writes in Choshen Mishphat (21,101). However to hear her other voice (her singing) its not found in this passage regarding his sister.
What the BASH writes, it appears to me that the voice of a woman not at the time of Kerias Shema is permitted, this is a single woman that isn’t in menstruation.
What it writes in Mishna Berura (75,117), in the name of Codifiers, that a single woman that is in menstruation is included in the arayos, her and all the virgins that are in a presumptive state of menstruation when they reach there time period to examine themselves (see there).
With regards to the sister there is no difference if she has reached the time to examine herself or not, because in all situations she is in the boundary of a ervah.
The MAV writes that it is forbidden to hear the singing of a single gentile woman. BASH also writes (108), that Ulla kissed the hands of his sisters, and it says in Talmud Shabbos (13A)a perfect righteous man and he knows himself that he won’t come to have any immoral thoughts (see there).
It appears from there that Ulla would be permitted to hear his sisters voice. However we cant compare ourselves to the holy Amoraim as it says on them in Chazal (Shabbas 112B), that these are not men, (Rashi explains there only angels).
See PAT (Even Haezer 21, 103) in the name of the Ritva, and also Rama, in Orach Chaim (75,63), that a voice he is accustomed to is not ervah, this is a voice that he is accustomed to, and so writes Shulchan Arach Harav (75,66),the voice of a woman ect, is ervah and its forbidden to say Shema when hearing it and according to the law not to pray there or say words of Torah.
However the sound of her voice since he is accustomed to it is not ervah, even a married woman,and even the sound of the woman, so along as he is able to concentrate his mind to the prayer, he doesn’t hear the voice (amidst his prayer) and doesn’t set his mind to her voice.
See Choshen Mishpat (21,109)hugging and kissing his younger sister who is 3 years old or younger,its not in intimacy of matrimony only affection of a kin, being all for the sake of Heaven, (END), and it must be examined.
If the intention of z”l, if its permitted only up to 3 years old or above 3 years old.
See Biur Halacha (75,61) that the uncovered arm of a woman (above the elbow), it it is forbidden to read Kerias Shema in front of her, this measurement is applicable to a child of even 3 years old and above and she is able to cohabit (see there).
Its possible that only regarding Kerias Shema it is stringent and from 3 years and onwards. It says in Sefer Chazon Ish (Orach Chaim 15,8)writes regarding Kerias Shema since regarding these the arm and leg (uncovered above the joint)is not ervah in principle only that the Sages forbade them to stop immoral thoughts and actions.
It appears that if the thinking of people because of there young age the Sages opinions lean towards to not forbidding, and there is no measurement of age rather according to the circumstances and size of there bodies (END).
It is possible also with regards to hearing the voice of his sister even if she is over 3 years old is not on the boundary of a older girl. This is implied by the words of the BASH (114)that he quoted in the name of the Choshen Misphat, thats it is permitted to kiss his younger sister (END). This is excluding that which it is written in the name of the Choshen Mishpat, that she is 3 years old, and its implied that even if she is older then 3 years its permitted, and it depends on the circumstances if her voice causes immoral thoughts (and this needs analysis), but a older girl it appears its clearly forbidden.