You can also enroll it in an obedience school to overcome separation anxiety. Dogs are frightened of loud noises and start chewing because of their fears. You can train your dog desensitization to the noises. Gradually expose it to the fears with you around and it will eventually accept and overcome its fears. When a dog is socially isolated or bored without play things, it starts to chew for its own recreation and entertainment.
Some dogs deliberately seek attention with negative behaviors.
You need to reinforce your dog for the good behaviors and ignore it for the bad ones. Also, remove all inappropriate objects and give your pet only its chewing toys. Disallow your dog to play with items that don't belong to it. Exercise your pet regularly so that it has sufficient play time. Dogs investigate objects with their mouths.