What are the ritual Shofar sounds?

These sounds or call are made with the Shofar for ritual use:

Tekiah - A long blast beginning in musical mid range and finishing as a high note.

Shvarim - Three staccato blasts. The duration of all three together is the length of a tekiah.

Truah - A long ululating or wailing sound. There are two main variants of the truah. One tradition uses nine seperate short calls in rapid sequence. The other is a long call with nine wavering ululations.

Tekiah Gdolah - This is a tekiah that you continue as long as you can. It comes at the end of the series of calls. The tekiah Gdolah is usually the last shofar calls. It is a very long blast used to announce the end of the holy day of Yom Kippur. Soma shofar blowers can hold a tekiah gdolah for more than a minute. This call is the mark of a good "ba'al tokiah" and requires a lot of practice to develop your wind. 

The Shofar in the Bible

The shofar in biblical times served a number of purposes:

1: Shofar of melody - This is the musical instrument in daily use whose sole purpose was to entertain the crowd and elude musical enjoyment by the masses. It is this instrument to whose sound kings were crowned. The shofar of song and melody is best described in Psalms 47, which is recited seven times, prior it's ceremonial sounding on the day of Rosh ha-Shana, "YHVH is gone up with a shout, Adonai with the sound of the Shofar. Sing praises to YHVH, sing praises: Sing praises unto our King, sing praises."

2: Shofar of war - The shofar in this role served as instrument of alarm to gather the defenders or to call to arm the troops to wage war as, for instance, in the times of Gideon the judge, "And the three hundred blew their shofar and Adonai set every man's sword against his fellow, even throughout all the host" It is in a similar way that the sound of the shofar calls the individual, through it's reverberating and unsettling tune, to repent as the prophet Amos declares "Shall a shofar be blown in a city, and the people not be afraid ?"

3: Shofar of revelation - As YHVH spoke the ten commandments, at the foot of Mount Sinai, presenting meanwhile the audio visual effects of all times…. we read in the scriptures, "And it came to pass on the third day in the morning, that there were thunders and lightnings and a thick cloud upon the mount, and the voice of the shofar exceeding loud so that all the people that were in the camp trembled…and when the voice of the shofar sounded long and waxed louder, Moses spoke and God answered him by a voice."

4: Shofar of freedom - This is the shofar of setting slaves free and of returning every one to their possession in the seventh (Shmitta) and fiftieth (Yovel) years. This was announced by the sound of the shofar as it is written in Leviticus 25, "…then shalt thou cause the shofar of the yovel to sound…ye make the shofar sound throughout all your land…and proclaim liberty throughout all the land unto all the inhabitants thereof." Thus we see that the shofar is the bearer of good tidings and comfort of peace and tranquility to the world and further, the shofar will be instrumental in gathering all the lost tribes onto the promised land to live in eternal peace and safety.