Thunderclap( Savage Species, p. 40)
You create a cone of deafening sound by clapping two limbs together.
You may, as a full-round action, clap two of your limbs together and create a cone of sound that starts at your position and continues out for a number of feet equal to 5 Ã— your Hit Dice. A storm giant using this feat creates a cone 95 feet (5 Ã— 19 Hit Dice) long. Creatures in the cone get a Fortitude save (DC 10 + 1/2 your Hit Dice + your Con modifier) to resist the effect. Those who fail their save are deafened for the duration of the encounter. Those who fail their save by 5 or more are also knocked down. See the Condition Summary in Chapter 3 of the DUNGEON MASTER's Guide for the results of being deafened and knocked down.
This effect automatically extinguishes unprotected flames (candles, torches, and the like).