Hearing

thumb|A drum produces sound via a vibrating membrane.

thumb|thumbtime=23|Video showing how sounds make their way from the source to the brain|upright=1.35 Hearing, or auditory perception, is the ability to perceive sounds through an organ, such as an ear, by detecting vibrations as periodic changes in the pressure of a surrounding medium. The academic field concerned with hearing is auditory science.

thumb|3D model of cochlea and semicircular canals The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus. A core component of the cochlea is the organ of Corti, the sensory organ of hearing, which is distributed along the partition separating the fluid chambers in the coiled tapered tube of the cochlea.

sound with a typical pitch; steady periodic sound; characterized by its duration, pitch, intensity (or loudness), and timbre (or quality)

sensory system used for hearing

alt=Image showing an audiologist testing the hearing of a patient inside a hearing booth and using an audiometer|thumb|upright=1.3|Audiological exam

term in acoustics

ability to pay attention to one conversation among many

thumb|Spectrograms of [[Thrush nightingale (Luscinia luscinia) and Common nightingale (Luscinia megarhynchos) singing help to reliably distinguish these two species by voice.]] Bioacoustics is a cross-disciplinary science that combines biology and acoustics. Usually, it refers to the investigation of sound production, dispersion and reception in animals (including humans). This involves neurophysiological and anatomical basis of sound production and detection, and relation of acoustic signals to the medium they disperse through. The findings provide clues about the evolution of acoustic mechan

thumb|New age portable digital audiometer An audiometer is a machine used for evaluating hearing acuity. They usually consist of an embedded hardware unit connected to a pair of headphones and a test subject feedback button, sometimes controlled by a standard PC. Such systems can also be used with bone vibrators to test conductive hearing mechanisms.

A soundscape is the acoustic environment as perceived by humans, in context. The term, originally coined by Michael Southworth, was popularized by R. Murray Schafer. There is a varied history of the use of soundscape depending on discipline, ranging from urban design to wildlife ecology to computer science. An important distinction is to separate soundscape from the broader acoustic environment. The acoustic environment is the combination of all the acoustic resources, natural and artificial, within a given area as modified by the environment. The International Organization for Standardization

Audiometry () is a branch of audiology and the science of measuring hearing acuity for variations in sound intensity and pitch and for tonal purity, involving thresholds and differing frequencies. Typically, audiometric tests determine a subject's hearing levels with the help of an audiometer, but may also measure ability to discriminate between different sound intensities, recognize pitch, or distinguish speech from background noise. Acoustic reflex and otoacoustic emissions may also be measured. Results of audiometric tests are used to diagnose hearing loss or diseases of the ear, and often

method used by some animals to determine the location of something by measuring the time it takes for an echo to return from it

thumb|upright=1.3|right|Equal-loudness contours The phon is a logarithmic unit of loudness level for tones and complex sounds. Loudness is measured in sones, a linear unit. Human sensitivity to sound is variable across different frequencies, so although two different tones may present an identical sound pressure to a human ear, they may be psychoacoustically perceived as differing in loudness. The purpose of the phon is to provide a logarithmic measurement (like decibels) for perceived sound magnitude, while the primary loudness standard methods result in a linear representation. A sound with

thumb|300px|right|Audiogram

Amusia is a musical disorder that appears mainly as a defect in processing pitch but also encompasses musical memory and recognition. Two main classifications of amusia exist: acquired amusia, which occurs as a result of brain damage, and congenital amusia, which results from a music-processing anomaly present since birth.

minimum sound level that an average individual can hear

biological process to identify the location or origin of a detected sound in direction and distance

sound with a sinusoidal waveform

annual campaign by the World Health Organization Office for the Prevention of Deafness

point at which pain begins to be felt

mechanical energy produced by the rapid contraction of the outer hair cells of the cochlea

neurodevelopmental disorder that affects how the brain processes sounds

The sone () is a unit of loudness, the subjective perception of sound pressure. The study of perceived loudness is included in the topic of psychoacoustics and employs methods of psychophysics. Doubling the perceived loudness doubles the sone value. Proposed by Stanley Smith Stevens in 1936, it is not an SI unit.

component in a sequence of stimuli

Concept in human perception of sound

hearing loss caused by occupational hazards

practices to avoid hearing damage from intentionally heard sounds

psychoacoustic phenomenon

injury to the eardrum as a result of a very loud noise

policy of routinely testing the hearing of babies soon after birth

Psychoacoustical phenomenon

effect that occurs when the perception of one sound is affected by the presence of another sound

process of hearing and understanding language

evaluation of the sensitivity of a person's sense of hearing

anatomic element

in phonetics, measure of how comprehensible speech is

sound-induced vertigo

Autophony (also tympanophony) is the unusually loud hearing of a person's own voice.

electrophysiological assessment of auditory system synchrony

thumb|Obstetric ultrasonography of [[twins at a gestational age of almost 9 weeks. The mother’s and the twins’ bodies have a higher echogenicity than the amniotic fluid around them. The standard representation is brighter color for higher echogenicity, giving the almost anechoic fluid an almost black appearance.]] Echogenicity (sometimes as echogenecity) or echogeneity is the ability to bounce an echo, e.g. return the signal in medical ultrasound examinations. In other words, echogenicity is higher when the surface bouncing the sound echo reflects increased sound waves. Tissues that have highe

subjective perception, when listening to a certain sound situation

measure of speech transmission quality

claim that presence of ultrasound has measureable reactions

hypothetical neural stimulation for altering states of consciousness