Cure Vanilla's first attack in Pretty Cure Perfume Preppy, "Pretty Cure Vanilla Echo", had her scream into a giant yellow megaphone made of light, producing soundwaves that went straight to the enemy, killing it as of episode 5. Word of God says that Cure Tangerine's upcoming power-up attack, "Pretty Cure Tangerine Silver Wail", has her scream out orange soundwaves which do the same thing. Beware the Nice Ones indeed.
This is one of the more common superpowers that turns up in Rise of the Galeforces, and one of the rare few to be used by more than two Supers. Apparently, the Sonic Scream, as it's officially called, used to be quite popular.
The story A New Order has Usagi use this in her first youma fight, and then keep using it in almost all of her subsequent fights. It isn't at all lethal, but it can make most villains curl up in a ball of pain.