An assistive listening device cap attaches to a headpiece of a cochlear implant behind-the-ear (BTE) unit, an other BTE unit, an earhook, or an external component unit to supplement or replace components thereof. The cap may receive signals from sources outside the BTE unit(s), earhook, and/or external component unit. The cap communicates with the BTE unit(s), earhook, and/or external component unit using direct, wired, or wireless technology.