Rosh Hashanah ראש השנה is also described in the Torah as Yom Teru’ah ,יום תרועה , the Day of Sounding the Shofar.
For those that wish to blow the shofar correctly, the order to practice is as follows:1) Tekiah—an uninterrupted blast lasting for several seconds. 2) Shevarim—three medium-length blasts. 3) Teruah—a minimum of nine very short blasts.
Within a synagogue the minimum of blasts to be heard to meet the mitzvah is 100, outside (such as in diaspora/Whidbey) you can be considered good to go after hearing a minimum of 30.