It is quite normal for Labradors to be afraid of the doorbell ringing since dogs have very sensitive hearing. Under the influence of such sounds, they can feel very sensitive. So what should you do if your Labrador is afraid of the doorbell?

　　If the reaction is to the sound of the doorbell, you can ask relatives or friends to frequently ring the doorbell, or record the doorbell sound on a tape and play it for the Labrador. Whenever the doorbell rings, the Labrador barks. After hearing it many times, the Labrador will get tired of it. Gradually, when guests ring the doorbell, it will stop barking indiscriminately.

　　If the reaction is to unfamiliar guests, then normally allow the Labrador to interact with a variety of people more often. This will gradually improve the behavior. (Source: PetsZone)