an adjective is a word used to modify a noun or a pronoun. Loud can be used as an adjective to describe something that makes a lot of sound or noise, such as loud cries or loud music.
Loud is usually used with nouns to describe a sound (e.g. loud laughter, loud music). It can also be used with verbs to indicate a sound of a particular intensity (e.g. speak loudly). It is usually followed by an adverb or adverb phrase (e.g. very loudly, extremely loud).
She laughed loudly at the joke.
He spoke too loudly during the meeting.
The audio was loud enough for everyone in the room to hear.
Loud can be used in either a positive or negative connotation. It should not be confused with other adjectives that describe sound, such as shrill or piercing. To maintain grammatical correctness, loud should be used as an adjective (e.g. loud noise) and not a noun (e.g. a loud).