Hello ! you seem to have developed post infective bronchial hyperactivity , which means to say , in some patients , the respiratory tract infection causes the airways to construct temporarily for few days . This causes difficulty for air to enter and exit through the airways causing the grumbling sound .The good news is this is a temporary phenomenon .Get a chest x-ray done . Ensure that you complete the course of your antibiotics . and also take Inhaled bronchodilators like Foracort , Budamate or Duolin inhalers for few weeks until your airways get back to their normalcy and your breathing is at ease .Avoid exposure to cold and dust m Hope my reply is of help . Do drop in your valuable feedback.