The outer ear is the external portion of the ear, which consists of the pinna and external auditory meatus. It gathers sound energy and focuses it on the eardrum. One consequence of the configuration of the external ear is to selectively boost the sound pressure 30- to 100-fold for frequencies around 3 kHz. This amplification makes humans most sensitive to frequencies in this range – and also explains why they are particularly prone to acoustical injury and hearing loss near this frequency.