Blowing the Shofar:
When is the Shofar blown? The Shofar is blown daily following Shacharis [and the daily recital of Tehillim, with exception to Shabbos in which it is forbidden to sound the Shofar]. [It is customary to blow the Shofar also during children’s gatherings.]
One who makes a mistake in blowing: If one made a mistake during the blow there is no need to repeat it, as these blows are merely a custom.
It is the custom of Ashkenazi Jewry to blow Shofar throughout the month if Elul. One begins to blow the Shofar for practice on the first day of Rosh Chodesh. From the second day and onwards, one blows nine blows [Tashrat, Tashat, Tarat] following Shacharis and the daily recital of Tehillim. One does not blow Shofar on Erev Rosh Hashanah unless one is blowing for practice in a closed room.
What is a congregation to do if they did not blow the Shofar after Shacharis?
The Shofar is to be blown after Mincha.
Must one stand when hearing the blows?
There is no source for such an obligation although practically the custom is to do so.
Does one fulfill the above custom of hearing Shofar in Elul through hearing the recording of a Shofar blowing?
No. One is required to hear the live sound of a person blowing a physical Shofar in order to fulfill this custom.
 Rama 581/1
The Rosh in his conclusion of Tractate Rosh Hashanah records the Pirkeiy Direbbe Eliezer 46 that on Rosh Chodesh Elul Moshe ascended to heaven to receive the 2nd tablets. On that day they blew the Shofar proclaiming Moshe’s ascent to the public so they do not make another calculation mistake as they did by the golden calf. Due to this the Sages instituted that every year one is to blow Shofar on Rosh Chodesh Elul for the purpose of arousing the people to repent and in order to confuse the Satan. The Rosh then concludes: This is the custom in Ashkenaz-to blow the Shofar in the morning and evening after prayers. The Tur 581 quotes his father and then writes “and there are those that increase in Selichos from Rosh Chodesh Elul”. In the Shulchan Aruch the Michaber 581/1 records only this latter custom of the Tur regarding saying Selichos and does not mention the blowing of the Shofar. The Rama however negates the custom of Selichos in Ashkenaz and states that they are rather accustomed to blow Shofar. From the wording of the Rama it implies that in exchange for the saying of Selichos throughout the month, the Ashkenazim blow Shofar. Perhaps the meaning behind this is that all Jewry begins to do some form of spiritual preparation in the month of Elul, the Sefaradim with the saying of Selichos, and the Ashkenazim with the blowing of the Shofar.
 Rama ibid; Rosh ibid; Tur ibid
Do Sefardim also blow Shofar during Elul? It is not the Sefaradi custom to blow Shofar after prayer during Elul. This follows the second opinion of the Tur which implies that those which increase in Selichos during Elul do not follow the custom of blowing the Shofar. This is implied from the Rama [and lack of mention of Michaber] that this custom only applies to Ashkenazim and not to Sefaradim. Nevertheless there are some Sefaradim that are accustomed to blow Shofar during their recital of Selichos in order to follow both opinions. [Kaf Hachaim 581/13] See Aruch Hashulchan 581/1 that writes all Jews are accustomed to blow Shofar during the month of Elul.
The reason behind blowing Shofar in Elul:
- On Rosh Chodesh Elul Moshe ascended to heaven to receive the 2nd tablets and on that day they blew the Shofar proclaiming Moshe’s ascent to the public. Due to this the Sages instituted that every year one is to blow Shofar on Rosh Chodesh Elul. [See Background from Pirkei Direbbe Eliezer]
- Blowing Shofar arouses fear of G-d, and leads one to repentance. [Tur ibid; Kitzur SHU”A 128/2]
- The verse states “Blow Shofar [for a] month”. [M”A 581/2; 28 days in Elul, as on Erev RH we don’t blow, and 2 days of RH for a total of 30-Levushei Serud]
- Blowing Shofar refrains the Satan from prosecuting the Jewish people, as he recalls the day in which the great Shofar will be blown which is the date of his prosecution and death. [Hosafos Rav Nechemia Medovrana p. 1362 in SH”A Admur]
- Blowing Shofar confuses the Satan in regards to the date of Rosh Hashanah. [Hosafos Rav Nechemia Medovrana p. 1362 in SH”A Admur]
Sefer Haminhagim p. 113 [English Edition]; Custom in Bach 592 based on Aruch; Darkei Chaim Veshalom 690; Likkutei Sichos 2/446; See Otzer Minhagei Chabad p. 7
The Bach 592 writes that based on the opinion of the Aruch [regarding blowing Tashrat-Tarat-Tashat in Musaf-See “The laws of Shofar” chapter 4/5] one is to blow 9 blows in order so people not think that one fulfills the obligation with less than these nine blows. He however concludes that the custom is not to do so possibly due to that they hold like the opinion of Rabbeinu Tam that argues on the Aruch [regarding the blows in Musaf and says one is only to blow Tashrat three times]. In Likkutei Sichos 2/446 the Rebbe states that the ten sounds correspond to the ten soul powers.
Other opinions: The custom of most communities is to only blow Tashrat. [Bach ibid based on Rabbeinu Tam; Kitzur SH”A 128/2; PiskeiyTeshuvos 581/3 ]
 The reason: One is to blow a total of nine blows in the order of Tashrat, Tashat, Tarat in order so people do not think that one fulfills the obligation with less than these nine blows. [Bach ibid] This follows the ruling of Admur in 592/5 that the best custom to follow is the custom of Aruch by Musaf and so rules Admur in the Siddur.
Blowing at night: The Rama records that there are places that likewise blow the Shofar at night. [Rama 581/1] This is not our custom today. [AruchHashulchan 581/1]
 590/19 regarding blows of after Musaf
Hisvadyos 1991 4/314 [printed in Shaareiy Halacha Uminhag 5/66; Shulchan Menachem 3/74]; Igros Moshe 4/21; See Chayeh Adam 1338/1; See also Rama 581/1 that there are places which blow also by Maariv.
Piskeiy Teshuvos 581/3
Sichas Balak 7th Tammuz
The reason: “Even the sounding of the Shofar in Elul, which is only to arouse Teshuvah, is not to be heard from a recorder as since it needs to arouse ones feelings of Teshuvah therefore it has to be done through a person, as words that come from the heart enter the heart”