If the noise is lower, the AC service may be the cause. Magnetic fields from transformers can cause humming. Mains transformers typically cause an AC magnetic field around them. This magnetic field can be copled to wiring, electronics or signal transformers and cause humming.
Baby oil benefits: ear. Mineral or baby oil is good from treating common ear problems, such as wax build-up. For those that are hard of hearing, we recommend using a few drops of heated baby oil before going to your ear specialist. Then pour the drops in your ear, keeping your head cocked. Hold for a few minutes.
If your newborn is circumcised, gently clean the area with warm water, and if your baby's doctor recommends it, put a dab of petroleum jelly on the penis or on the front of the diaper for a few days to ease discomfort from friction against the diaper. You might also be advised to apply a new bandage on the penis during diaper changes for a few days.