Audio system measurementsAudio system measurements are a means of quantifying system performance. These measurements are made for several purposes. Designers take measurements so that they can specify the performance of a piece of equipment. Maintenance engineers make them to ensure equipment is still working to specification, or to ensure that the cumulative defects of an audio path are within limits considered acceptable. Audio system measurements often accommodate psychoacoustic principles to measure the system in a way that relates to human hearing.
HearingHearing, 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. Sound may be heard through solid, liquid, or gaseous matter. It is one of the traditional five senses. Partial or total inability to hear is called hearing loss.
Absolute threshold of hearingThe absolute threshold of hearing (ATH) is the minimum sound level of a pure tone that an average human ear with normal hearing can hear with no other sound present. The absolute threshold relates to the sound that can just be heard by the organism. The absolute threshold is not a discrete point and is therefore classed as the point at which a sound elicits a response a specified percentage of the time. This is also known as the auditory threshold. The threshold of hearing is generally reported in reference to the RMS sound pressure of 20 micropascals, i.
HangulThe Korean alphabet, known as Hangul (ˈhɑːnguːl ; ) in South Korea and Chosŏn'gŭl () in North Korea, is the modern official writing system for the Korean language. The letters for the five basic consonants reflect the shape of the speech organs used to pronounce them, and they are systematically modified to indicate phonetic features; similarly, the vowel letters are systematically modified for related sounds, making Hangul a featural writing system.
Auditory processing disorderAuditory processing disorder (APD), rarely known as King-Kopetzky syndrome or auditory disability with normal hearing (ADN), is a neurodevelopmental disorder affecting the way the brain processes sounds. Individuals with APD usually have normal structure and function of the outer, middle, and inner ear (peripheral hearing). However, they cannot process the information they hear in the same way as others do, which leads to difficulties in recognizing and interpreting sounds, especially the sounds composing speech.
Korean phonologyThis article is a technical description of the phonetics and phonology of Korean. Unless otherwise noted, statements in this article refer to South Korean standard language based on the Seoul dialect. Morphophonemes are written inside double slashes (⫽ ⫽), phonemes inside slashes (/ /), and allophones inside brackets ([ ]). Korean has 19 consonant phonemes. For each plosive and affricate, there is a three-way contrast between unvoiced segments, which are distinguished as plain, tense, and aspirated.
Impedance matchingIn electronics, impedance matching is the practice of designing or adjusting the input impedance or output impedance of an electrical device for a desired value. Often, the desired value is selected to maximize power transfer or minimize signal reflection. For example, impedance matching typically is used to improve power transfer from a radio transmitter via the interconnecting transmission line to the antenna. Signals on a transmission line will be transmitted without reflections if the transmission line is terminated with a matching impedance.
PerceptionPerception () is the organization, identification, and interpretation of sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous system, which in turn result from physical or chemical stimulation of the sensory system. Vision involves light striking the retina of the eye; smell is mediated by odor molecules; and hearing involves pressure waves.
Korean languageKorean (South Korean: , hangugeo; North Korean: , chosŏnmal) is the native language for about 80 million people, mostly of Korean descent. It is the official and national language of both North Korea and South Korea (geographically Korea). The two countries have established standardized norms for Korean, and the differences between them are similar to those between Standard Chinese in mainland China and Taiwan, but political conflicts between the two countries have highlighted the differences between them.
DecibelThe decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a power ratio of 101/10 (approximately 1.26) or root-power ratio of 10 (approximately 1.12). The unit expresses a relative change or an absolute value. In the latter case, the numeric value expresses the ratio of a value to a fixed reference value; when used in this way, the unit symbol is often suffixed with letter codes that indicate the reference value.
Letter (alphabet)A letter is a segmental symbol of a phonemic writing system. The inventory of all letters forms an alphabet. Letters broadly correspond to phonemes in the spoken form of the language, although there is rarely a consistent and exact correspondence between letters and phonemes. The word letter, borrowed from Old French letre, entered Middle English around 1200 AD, eventually displacing the Old English term bōcstæf (bookstaff). Letter is descended from the Latin littera, which may have descended from the Greek "διφθέρα" (, writing tablet), via Etruscan.
Cherokee syllabaryThe Cherokee syllabary is a syllabary invented by Sequoyah in the late 1810s and early 1820s to write the Cherokee language. His creation of the syllabary is particularly noteworthy as he was illiterate until the creation of his syllabary. He first experimented with logograms, but his system later developed into a syllabary. In his system, each symbol represents a syllable rather than a single phoneme; the 85 (originally 86) characters provide a suitable method for writing Cherokee.
