Previous:  The Shevarim is made up of three medium blows. A number of customs exist in regards to how to sound these medium blows. Some are accustomed to sound it as follows: “Tuuu-Tuuu-Tuuu”. Others are accustomed to sound it as follows: Teuto-Teuto-Teuto. Others are accustomed to sound it as follows: Teuto-Uto-Uto. The widespread Chabad custom is like the 3rd custom mentioned here.
Teruah: The Teruah is a number of very short blows blown consecutively and sounds like this: “Tu-Tu-Tu-Tu-Tu-Tu-Tu-Tu-Tu-Tu-Tu-Tu-Tu-Tu”
 Piskeiy Teshuvos 590/2
 Polish and Hungarian Chassidic Jewry
 Lithuanian and Russian Jewry; Custom of the Rebbe as brought in Otzer Minhagei Chabad p.121
The advantage of this custom: The advantage of this custom is that one is able to measure the three Terumatin required in the blow. [Mikraeiy Kodesh 17; See Halacha 7]
 Rav Yaakov Landau in name of the Rebbe Rashab, brought in Otzer Minhagei Chabad p.121; Mikraeiy Kodesh 17 in the name of Rav Chaim Brisker.