An earphone assembly for an in-ear listening device is disclosed. The earphone assembly has an inner housing comprising a nozzle, configured to receive a sleeve for placement into a user's ear, and a balanced armature motor assembly. The balanced armature motor assembly is mounted in the inner housing so as to form an acoustical seal between the inner housing and the balanced armature motor assembly. The earphone assembly also includes an outer housing configured to receive the inner housing. The inner housing can comprise a recess for receiving a paddle of the balanced armature motor assembly. Alternatively, the outer housing can be formed with a nozzle for receiving a sleeve for placement into a user's ear canal, and the inner housing can comprise a spout, which is received in a recess in the outer housing.