Hello Thanks for writing to H.C.M. for your query. I have gone through your query regarding crackling sound in your ear during swallowing along with acute pain in ear. As you said that you are suffering from cold for about a month and you have not taken any medication for it. Considering your symptoms in all aspect it is likely to be upper respiratory tract infection involving your nose, sinuses and throat and from throat infection reached to ear by eustachian tube. In the ear this is causing acute inflammation which is technically called as acute otitis media. During the act of swallowing as soon as eustachian opening try to open acute pain is felt. To get relief you should take antibiotic, anti inflammatory, decongestant and steam inhalation. No ear drop to be use as it may harm. With Regards.