Humming from left ear

Hi, welcome to the ehealth forum and I am glad to help you.
You seem concerned by the plugging of left ear for a couple of days with humming sounds.
There are a number of causes of an ear feeling blocked or muffled. One is negative middle ear pressure. This is caused by a malfunctioning Eustachian tube. The Eustachian tube connects the middle ear to the back of the nose. It opens and closes when we swallow or yawn, allowing the pressure to equalize between the middle ear and the outside world. When it does not work properly, negative pressure develops in the middle ear, making the ear feel blocked. Common causes for Eustachian tube problems include: Allergies, colds, sinus infections, barotraumas (injury to the ear from changes in atmospheric pressure).
When the Eustachian tube is severely impaired, fluid can build up in the middle ear. This causes hearing to decrease. A middle ear infection can do the same. After the infection clears, the blockage can go on until the Eustachian tube is back to normal. Pain and swelling around the jaw joint (temporomandibular joint) often cause a blocked sensation in the ear. The exact cause of this sensation is not clear. A change in hearing, such as sudden hearing loss, can also make the ear feel blocked. And a condition called otosclerosis can block one's hearing. Otosclerosis is the abnormal formation of spongy bone in the ear.
When ear blockage is continuing as in your case, an exam by an ear nose and throat specialist (otolaryngologist) and a hearing test (an audiogram) are needed. You may need more tests depending upon the findings of the exam and first hearing test. Treatment can then be directed at the cause to help eliminate the problem.
Hope this helps. Take care.
Note: This post is not to emphasise final diagnosis as the same cannot be made online and is aimed just to provide medical information and no treatment suggested above be taken without face to face consultation with health care professional.