The best way to help a dog overcome its fear of loud noises is to desensitize it gradually. Start by playing recordings of the noise at a very low volume. If the dog remains calm, reward it with a treat. As the dog gets used to the sound, gradually increase the volume until it is at a normal level. Repeat this process as often as needed until the dog no longer shows signs of fear. Additionally, providing your dog with a safe space to retreat to when they are feeling scared can help them to cope better with loud noises.