Monday, August 25, 2014

Feline Sense and Scents-ability: Part 1: Hearing


Veiny Cat Ear from fantasystock.deviantart.com | Exclusively Cats Veterinary Hospital, Waterford, MI
Cat Ear from fantasystock.deviantart.com

Feline Sense and Scents-ability


Even though cats have the same five senses humans do, their perception of the world is much different. Sometimes, trying to understand a cat’s point of view can help shed some light on problems you may be having with your cat.

HEARING


Feline hearing is functionally the same as human hearing. The pinna, or outer portion of the ear, collects sound waves and translates them down the ear canal. In humans, the ear canal is a straight shot to the ear drum, while cats have a vertical canal connected to a horizontal canal in an “L” shape from the top of the head, straight down and then turning inward. Once the sound waves have rounded the corner of the ear canal, they cause the eardrum to vibrate, stimulating the ossicles of the middle ear (tiny bones called the malleus, incus and stapes - otherwise known as the hammer, anvil and stirrup). These ossicles transmit the sound waves to the cochlea.
Cat Ear Anatomy | Exclusively Cats Veterinary Hospital, Waterford, MI
Cat ear anatomy

The cochlea is a fluid-filled structure in the middle ear. The sound waves are translated to fluid waves in the cochlea that are then sensed by nerves connected to fine hairs that float in the fluid and is then sent on to the brain for interpretation. This is the area that a human “cochlear implant” stimulates to help correct hearing loss. The feline cochlea has 3 complete turns while the human cochlea only has 2.75 turns. They have 10,000 more auditory nerves than humans. Near the cochlea is another fluid- and carbonate crystal-filled structure called the vestibular apparatus that is in charge of balance.

Cats are exquisitely adept at locating prey. They can distinguish between two different sound sources 8 cm apart (shorter than the length of an iPhone) at 2 yards and 40cm apart (about 1 foot, or a little longer than 3 iPhones) at 20 yards. They can hear a rustling mouse 20-30 yards away. They can hear 10 distinct octaves of notes vs. humans’ 8.5 octaves. They even hear one octave above their canine counterparts.

Chart courtesy of www.watchingtheworldwakeup.blogspot.com
There are 4 sets of muscles that control the motion of the cat’s external ear flap, or pinna, and allow it to rotate 180 degrees to catch a sound and orient on it. You can use this information to make playtime more interesting for your cat. Make “hide and seek” with toys more challenging by using quieter, less obvious “prey”. Test your cat’s auditory awareness with a tiny crinkle from a crinkle-toy. See if they notice.  

Even though you think they can’t hear you, don’t yell at your cat! He can hear you, he just isn’t listening to you.

When your cat is sleeping it is still attentively listening, scanning for audible information, which is why your “soundly sleeping cat” is standing right at your feet the second you open a can of food.