Electronic HPDs are available in both earmuff and custom earplug styles. Earplug style hearing protection devices are designed to fit in the ear canal. Earmuffs are easy to wear and often provide a more consistent fit than an earplug. There is a jack for a mono earplug. These differences are most likely attributed to incorrect insertion or poor earplug fit. There was also a jack for a mono earplug. Training for earplug use includes&colon; insertion, a seal check, depth check, removal, cleaning, and replacement. The maximum age determined from earplug laminae for a pygmy whale is 73 years (n=1133). The figurines often have earplug flares. The earplug is a 4 segment type.