Disclosed herein is a modular earphone segment and method of manufacturing, the modular earphone segment housing an acoustic waveguide therein, the acoustic waveguide including between an inner end and an outer end a series of acoustic horns intercalated between a series of transition regions and the modular earphone segment including an acoustic seal module, a body module and an acoustic transmission module, the acoustic seal module being configured to be connected to the body module by releasably coupling means and the body module being configured to be connected to the acoustic transmission module by connecting means such that, when connected, the acoustic seal module, the body module and the acoustic transmission module are acoustically coupled.