Amplifiers; Acoustic amplifiers; Acoustic amplifiers for mobile devices; Assistive listening device not for medical purposes; Audio amplifiers; Audio headphones; Audio mixers; Audio speakers; Batteries for use in hearing aids; Conical attachment to an audio speaker for diffusing and distributing sound as it is transmitted from the speaker; Digital sound processors; Earphones and headphones; Handheld electronic units for adjusting sound levels in hearing aids; Loud speaker systems; Loud speakers; Loudspeakers with built in amplifiers; Loudspeakers, headphones, microphones and CD players; Portable vibration speakers; Signal processors for audio speakers; Sonar equipment and parts thereof; Stetoclip hearing aid listeners