The sound that a seagull makes is commonly referred to as a "call" or a "cry." Seagulls produce a variety of vocalizations, including squawks, screams, and a distinctive "mew" sound. The "mew" call is often associated with seagulls and is a high-pitched, plaintive sound. It is often used by seagulls for communication purposes, such as attracting mates, establishing territory, or signaling danger.