Many cat owners notice a small flap on the outer edge of their cat’s ears. This distinct feature, often called Henry’s Pocket, plays a role in a cat’s remarkable sensory abilities. Understanding this unique characteristic provides insight into the feline auditory system.
Cat Ear Anatomy
The small, skin-covered pouch on the lower, outer edge of a cat’s ear is formally known as the cutaneous marginal pouch, though it is more commonly called Henry’s Pocket. This distinct fold of skin creates a small pocket or slit at the base of the external ear, or pinna. This anatomical feature is also present in other mammals, including some dog breeds, bats, and weasels.
The pinna is the visible, triangle-shaped part of the ear that collects and directs sound waves into the ear canal. Henry’s Pocket appears as a slight indentation or slit, composed of a thin fold of skin.
The Purpose of the Flap
The precise function of Henry’s Pocket remains a subject of scientific speculation. One prominent theory suggests this pouch aids in sound localization, helping cats pinpoint the origin of sounds with greater accuracy. It may enhance the detection of high-pitched sounds, characteristic of small prey. This could occur by acting as a “muffler” for lower-pitched sounds, allowing higher frequencies to be more clearly received and amplified.
Another hypothesis proposes that the flap helps funnel sound into the ear canal, refining auditory input. It may also contribute to the ear’s ability to move efficiently, adding flexibility for ear positioning. The flap might also play a part in subtle communication cues by facilitating ear flattening.
Enhanced Feline Hearing
Cats possess highly developed hearing capabilities, integral to their predatory nature and survival. Their outer ears, or pinnae, are exceptionally mobile, controlled by approximately 32 muscles in each ear. This musculature allows cats to rotate their ears independently by up to 180 degrees. This range of motion enables them to precisely direct their ears toward faint or distant sounds, functioning much like individual radar dishes.
Feline hearing spans a broad frequency range, typically from about 48 Hz up to 85 kHz. This range significantly surpasses human hearing, which generally peaks around 20 kHz. Cats’ ability to detect ultrasonic sounds, those above the human hearing threshold, is crucial for hunting rodents and other small prey that communicate using high-frequency vocalizations. The specialized anatomy of the ear, including Henry’s Pocket, contributes to this auditory prowess, allowing cats to distinguish sounds just inches apart from several feet away.