Yoohooing is a type of shout or call that is used to grab someone's attention. When looking for synonyms for this word, there are a number of options available. One similar word is bellowing, which is a loud and deep shout that is intended to carry over a distance. Another synonym is hollering, which refers to a loud and sudden shout that is often used to express excitement or surprise. Other options include yelling, shouting, and calling out. All of these words share the basic idea of making a loud noise to get someone's attention, but each has its own unique connotations and nuances.