In physiology

Physiology

Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...

, tonotopy (from Greek tono- and topos = place) is the spatial arrangement of where sounds of different frequency are processed in the brain. Tones close to each other in terms of frequency are represented in topologically

Topology

Topology is a major area of mathematics concerned with properties that are preserved under continuous deformations of objects, such as deformations that involve stretching, but no tearing or gluing...

 neighbouring regions in the brain. Tonotopic maps are a particular case of topographic

Topographic map (Neuroanatomy)

A topographic map is the ordered projection of a sensory surface, like the retina or the skin, or an effector system, like the musculature, to one or more structures of the central nervous system...

 organization, similar to retinotopy

Retinotopy

Retinotopy describes the spatial organization of the neuronal responses to visual stimuli. In many locations within the brain, adjacent neurons have receptive fields that include slightly different, but overlapping portions of the visual field. The position of the center of these receptive fields...

 in the visual system.

Tonotopy in the auditory system begins at the cochlea

Cochlea

The cochlea is the auditory portion of the inner ear. It is a spiral-shaped cavity in the bony labyrinth, making 2.5 turns around its axis, the modiolus....

, the small snail-like structure in the inner ear that sends information about sound to the brain. Different regions of the basilar membrane

Basilar membrane

The basilar membrane within the cochlea of the inner ear is a stiff structural element that separates two liquid-filled tubes that run along the coil of the cochlea, the scala media and the scala tympani .-Function:...

 vibrate at different sinusoidal frequencies. The auditory nerves that transmit information from different regions of the basilar membrane therefore encode frequency tonotopically. This tonotopy is maintained in the human vestibule cochlea nerves cortex

Cerebral cortex

The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...

, that part of the brain

Brain

The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

 that receives and interprets sound information:

• sounds of low pitch project into the anterolateral aspect of Heschl's gyrus
• sounds of high pitch project deeply into the lateral fissure (which houses Heschl's gyrus).

Tonotopy is present in animals including humans and in cricket

Cricket

Cricket is a bat-and-ball game played between two teams of 11 players on an oval-shaped field, at the centre of which is a rectangular 22-yard long pitch. One team bats, trying to score as many runs as possible while the other team bowls and fields, trying to dismiss the batsmen and thus limit the...

s, where it is part of ultrasound avoidance.