1. The string ends inside your harp are vibrating
If the ends of your harp strings are too long, they can touch the wood of your harp and make a buzzing sound.
To fix it: Reach inside the soundbox of your harp (the part that leans against your body) and trim any long string ends with a pair of scissors/wire cutters.
2. Your strings need to be replaced
When your harp strings get old, 2 things can happen:
a) The wire wrapping on the lower strings can come loose
b) Strings made of gut can get frayed as they age
In both cases, the loose ends can vibrate and make a buzzing sound as you play.
To fix it: Just replace those strings! Easy.
3. The screws under your harp are loose
If your harp has any kind of legs, they are attached to your harp by screws or fit into a metal plate that is screwed onto the harp.
If these screws come loose, the metal can vibrate against your harp, causing a buzz. Sometimes it only buzzes when you play certain notes!
To fix it: Turn your harp over and see if any of the metal bits have come loose. If so, tighten the screws.
4. A string is hitting the lever as it vibrates
If your harp hasn’t been regulated in a while, it can gradually get to the point where a string is too close to its lever. Even though the lever is not engaged, the string touches it as it vibrates.
To fix it: Have your harp serviced and the harp technician will re-align the strings and levers.
5. The screws on a lever are loose
You can tell if this is the problem by a simple test: If there is a buzz when the lever is engaged (up) but not when it is down, you have yourself a loose lever!
To fix it: Use the appropriate tool for your harp to tighten the screws on the offending lever.
6. Something in the room is vibrating
Sometimes the resonance if a certain note on your harp makes a totally unrelated object in the room vibrate! Drum kits are often culprits, but it could also be something as simple as a pair of glasses on a glass table.
To fix it: Remove the buzzing item from the room you practice in!