Abstract: An apparatus includes a first and a second earbud and a case. The case is configured to provide an enclosure for the first and the second earbud and detect an insertion of either of the first earbud or the second earbud in the enclosure by using detection of a current provided to at least one of the first earbud and the second earbud.

Abstract: An apparatus includes of a first earbud and a second earbud, each including an interface chip and a case. The case includes a case interface chip configured to communicate data with, and transfer power to, interface chips of the first earbud and the second earbud. The case also includes a housing to provide enclosures for the first earbud and the second earbud. The case interface chip is mated with interface chips of the first earbud and the second earbud when the first earbud and the second earbud are inserted in the housing, and wherein the case, the first earbud, and the second earbud are configured to operate at a multiple, different bias voltage levels.

Abstract: A case can communicate with one or more earbuds to obtain information related to the earbuds, such as a battery charge level of the earbud. Due to the interface circuits within the case and the earbuds, the case can obtain the information from a power management unit of the earbud without first communicating with a processor (serving as the central processing unit) of the earbud. As a result, the processor can be powered down, i.e., inactive, and the case can still communicate with the earbud. Examples in which the processor can be powered down include when the earbud is in the case and not in use/service by a user, or when the earbud battery charge level is relatively low.