OHC

OHC is an acronym that can refer to multiple concepts depending on the context. The most common uses appear in biology and automotive engineering, but the abbreviation also appears in various other fields where the exact meaning varies by discipline.

In biology, OHC most often stands for outer hair cells, which are specialized sensory cells located in the organ of Corti within the cochlea of the inner ear. Outer hair cells play a key role in the amplification and sharp tuning of sound, a process known as cochlear amplification. They change length in response to electrical potentials, a motility mechanism facilitated by the motor protein prestin. This electromotility enhances auditory sensitivity and frequency discrimination and is also linked to otoacoustic emissions, sounds produced by the ear. Damage or loss of outer hair cells—due to noise exposure, ototoxic substances, or aging—can reduce hearing acuity and the precision of frequency perception.

In automotive engineering, OHC denotes overhead camshaft engines, in which the camshaft is located in the cylinder head above the valves. This arrangement allows for higher engine speeds and more precise valve timing compared with older overhead-valve designs. Modern implementations often use either a single or double overhead camshaft (SOHC or DOHC) and may include variable valve timing and other performance-enhancing technologies.

Other uses of OHC exist across domains and typically require contextual clarification. In summary, OHC most commonly identifies outer hair cells in hearing science or overhead camshaft configurations in engines, with meaning varying by field.