Digital hearing aids; Ear plugs for medical purposes; Ear plugs for noise reduction; Ear plugs for sleeping; Ear plugs for soundproofing; Ear plugs for soundproofing, other than for medical use; Ear plugs for swimming; Ear plugs for swimming purposes; Ear plugs for attenuation of selected noise frequencies, ear plugs for noise attenuation; Electric hearing aids; Electrical hearing aids; Hearing aids; Hearing aids for the deaf