Buzzing in the ear when the finger is close to the ear is due to the finger in the auricle, the mouth of the ear canal to form a narrow gap, the airflow through here, can play a role in local acceleration, the friction sound generated in the small space closer to the ear canal, and thus can be perceived as a buzzing phenomenon in the ear.
The auricle not only collects sound waves to the outer ear canal, it also has a gain effect on sound pressure. When the finger is close to the ear, and close to the mouth of the external auditory canal, the air flow in between creates friction between the finger surface and the auricle, which acts as an amplifier. Into the ear canal back of the perception and the appearance of buzzing in the ear performance.
This is the acoustic structural characteristics of the outer ear sound and aerodynamic effects of the integrated embodiment, is a normal physiological phenomenon. If there is any other discomfort, it is recommended to consult an ear, nose and throat specialist.