How might the swim bladder structures of Papyrocranus improve hearing?

In the African fish genus Papyrocranus, the swim bladder features diverticula—outpocketings of the organ—that physically penetrate the skull. This anatomical arrangement is believed to improve hearing by creating a direct connection between the gas-filled swim bladder and the auditory region of the head.1

In many teleost fishes, the swim bladder acts as a resonating chamber that can enhance sound reception. By extending into the skull, these diverticula likely facilitate the transmission of sound-induced vibrations to the inner ear, helping the fish detect acoustic signals more effectively. This mechanism is a specialized adaptation within the osteoglossomorph group, similar to how other species utilize air sacs or Weberian ossicles to bridge the acoustic impedance gap between the water and the fish's sensory tissues.231