How to blow a t'rua

Question

How does one effect a t'rua when blowing a shofar on Rosh Hashana? The airflow must be stopped and started repeatedly in a short time, but it can, I suppose, be stopped either

• at the glottis,
• at the narrow end of the shofar (by blocking it with the tongue), or
• anywhere in between (say, by effecting a velar stop)

— or, indeed, not by blocking the flow of air but simply

• by repeatedly pausing exhalation with the diaphragm.

Is/are any of these mandated/barred by halacha? Which is/are commonly used or not used, and why?

Answer 1

The sefer "Teka BeShofar" says that there are two methods for producing a teruah: "The common way," and "the simple way."

The Common Way: Air stream is held steady, and the sounds are formed by moving the tongue in and out of the shofar's opening. This is the most natural way, but it has two drawbacks: 1) Most people cannot do this fast enough to form the sounds properly; 2) It runs a serious risk of filling the shofar with spittle.

The Simple Way: Tongue never comes near the shofar. Rather, continuously strike the tongue against the roof of the mouth, as if to make a "Tee" or "Too" sound. The Syrian teruah has minimal break between the sounds, and is produced by using "li" instead of "tee". [The Yekkishe teruah (Frankfurt-on-Main) is warbled, with no break at all, and the modulation is controlled from the lungs. Very difficult to do without experience.]

Answer 2

While not directly answering your last question, I myself have done it two ways. One is by using my tongue to block and then unblock the airflow to the shofar. Blocking the shofar with your tongue directly tastes really bad, so just bringing the tongue to the top of your mouth is easier. It's also the most common way of doing it.

However for myself, I find that using my diaphram as if I am heavily sobbing or laughing has a more consistent sound as well as being less prone to error. My kavanah is also stronger when doing it that way as it reminds me more of Sisra's mother :) It also requires much more practice to be able to do it that way in the first place.