Every major BIOS manufacturer has a unique set of beep codes that can be generated during their POSTs. See How To Troubleshoot Beep Codes for more information.
Important: Computer systems without an internal speaker will not be capable of producing a beep code. POST errors that don't display on screen will have to be diagnosed with a POST test card.
Note: With many motherboards, the BIOS produces a single, short beep code as an "all systems clear" notification. This single beep code isn't an issue that needs troubleshooting.