A Study on Imbalanced Sound Sensitivity of BA Earphones Inducing Deafness

One of the popular ways to use smartphones in public places without disturbing others is to use them with earphones. Earphones are used by people of all ages for listening to music, watching sports/television programs, or even talking to someone over the phone. These devices can be generally classified into two types based on their driver unit, dynamic and BA (Balanced Armature). Dynamic type earphones perform relatively poor in withholding all the sound, letting some sound leak out. On the other hand, BA type earphones fit snuggly into the ears and prevent sound leak. Simultaneously, the users are being blocked out from outside noise. This paper will investigate the volume imbalance between the left and the right BA earphones using a coupler, and how users perceive the volume levels differently. The difference in voltage between the left and the right ones was significant, having 0.8mV with 43.9mV on the left and 44.7mV on the right to form 94dBSPL. This imbalance may cause noise induced deafness when continuously using earphones.