Over-The-Air Evaluation of User Body Loss for Popular In-Ear Bluetooth Earbuds

Wireless earbuds have become the preferred electronic device for listening to music and for hands-free talking. The combined radio performance of the earbud and the handset determines the quality of the established communication link and hence the quality of the user experience. This paper presents an extensive comparative study of five common Bluetooth earbuds, where the transmit performance, in terms of total radiated power (TRP), is investigated. The measurements are conducted for the right-side earbud and for the low and high ends of the Bluetooth frequency spectrum. Moreover, two scenarios are considered; 1) the earbud is placed in free space; and 2) the earbud is placed in a person’s ear. For the latter case, a total of 12 volunteers are involved in the measurement campaign. Measurements show that the mean performance deterioration, due to the placement of the earbud in the person’s ear, ranges from 3 to 6 dB across the tested earbuds.