发出(fā chū) - to give out, to emit; to send out, to issue in Mandarin

发出 covers two families of object. Physical emissions come first: sounds, light, heat, smells. 发出声音, 发出光, 发出气味. Then documents and signals: 发出通知, 发出命令, 发出邀请, 发出警告.

The pattern is always source plus 发出 plus the thing emitted. The source is the grammatical subject, so it is the machine that 发出声音, not the person hearing it. English lets you say "a noise came out of the machine"; Mandarin much prefers the machine as the actor.

Do not stretch it to sending messages to a person. For that use 发 alone (发短信, 发邮件) or 发送. And keep it apart from 发生 (to happen) and 发现 (to discover), which share the first character and trip up learners who read too fast.