The gorilla chest beat is one of the most emblematic sounds in the animal kingdom, even working its way into our informal speech signifying overblown advertisement of one’s own achievements. However, until recently it was unclear what information gorillas were conveying when they gave these impressive displays. A team of international researchers show that chest beats reliably indicate the body size of the chest beater. Body size indicates competitive ability in gorillas. Therefore this information is likely to be crucial for rival males as well as females in influencing mate choice.