Whispering is an unvoiced mode of phonation in which the vocal folds are abducted so that they do not vibrate. Supralaryngeal articulation remains the same as in normal speech. In normal speech, the vocal folds alternate between states of voice and voicelessness. In whispering, only the voicing segments change, so that the vocal folds alternate between whisper and voicelessness; because of this, implementing speech recognition for whispered speech is more difficult, as the characteristic spectral range needed to detect syllables and words is not given through the total absence of tone. More advanced techniques such as neural networks may be used, however. There is no symbol in the IPA for whispered phonation, since it is not used phonemically in any language. However, a sub-dot under phonemically voiced segments is sometimes seen in the literature, as for whispered should. Whispering is used to limit the hearing of speech to listeners who are nearby. Loud whispering, known as a stage whisper, is used only for dramatic or emphatic purposes.
Whispering takes less effort to vocalize than a normal speech pattern. This is. However, while it takes less effort to produce a whisper, it tires out the vocal folds more quickly. A number of species of animals have been observed to whisper, including the cotton-top tamarin and the barbastelle bat; the reasons for animal whispering vary, are not understood, but whispering among the tamarins appears to serve a social purpose, while the species of bats appears to whisper in order to evade detection by its particular prey, eared moths. Aspiration Chinese whispers Cocktail party effect Egressive sound vs. ingressive speech Whispering campaign Whispering gallery Whispery voice Other forms of unvoiced vocalization: gasping and panting Autonomous sensory meridian response Functional Neuroanatomy of Human Vocalization: An H215O PET Study
International Standard Serial Number
An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication, such as a magazine. The ISSN is helpful in distinguishing between serials with the same title. ISSN are used in ordering, interlibrary loans, other practices in connection with serial literature; the ISSN system was first drafted as an International Organization for Standardization international standard in 1971 and published as ISO 3297 in 1975. ISO subcommittee TC 46/SC 9 is responsible for maintaining the standard; when a serial with the same content is published in more than one media type, a different ISSN is assigned to each media type. For example, many serials are published both in electronic media; the ISSN system refers to these types as electronic ISSN, respectively. Conversely, as defined in ISO 3297:2007, every serial in the ISSN system is assigned a linking ISSN the same as the ISSN assigned to the serial in its first published medium, which links together all ISSNs assigned to the serial in every medium.
The format of the ISSN is an eight digit code, divided by a hyphen into two four-digit numbers. As an integer number, it can be represented by the first seven digits; the last code digit, which may be 0-9 or an X, is a check digit. Formally, the general form of the ISSN code can be expressed as follows: NNNN-NNNC where N is in the set, a digit character, C is in; the ISSN of the journal Hearing Research, for example, is 0378-5955, where the final 5 is the check digit, C=5. To calculate the check digit, the following algorithm may be used: Calculate the sum of the first seven digits of the ISSN multiplied by its position in the number, counting from the right—that is, 8, 7, 6, 5, 4, 3, 2, respectively: 0 ⋅ 8 + 3 ⋅ 7 + 7 ⋅ 6 + 8 ⋅ 5 + 5 ⋅ 4 + 9 ⋅ 3 + 5 ⋅ 2 = 0 + 21 + 42 + 40 + 20 + 27 + 10 = 160 The modulus 11 of this sum is calculated. For calculations, an upper case X in the check digit position indicates a check digit of 10. To confirm the check digit, calculate the sum of all eight digits of the ISSN multiplied by its position in the number, counting from the right.
The modulus 11 of the sum must be 0. There is an online ISSN checker. ISSN codes are assigned by a network of ISSN National Centres located at national libraries and coordinated by the ISSN International Centre based in Paris; the International Centre is an intergovernmental organization created in 1974 through an agreement between UNESCO and the French government. The International Centre maintains a database of all ISSNs assigned worldwide, the ISDS Register otherwise known as the ISSN Register. At the end of 2016, the ISSN Register contained records for 1,943,572 items. ISSN and ISBN codes are similar in concept. An ISBN might be assigned for particular issues of a serial, in addition to the ISSN code for the serial as a whole. An ISSN, unlike the ISBN code, is an anonymous identifier associated with a serial title, containing no information as to the publisher or its location. For this reason a new ISSN is assigned to a serial each time it undergoes a major title change. Since the ISSN applies to an entire serial a new identifier, the Serial Item and Contribution Identifier, was built on top of it to allow references to specific volumes, articles, or other identifiable components.
Separate ISSNs are needed for serials in different media. Thus, the print and electronic media versions of a serial need separate ISSNs. A CD-ROM version and a web version of a serial require different ISSNs since two different media are involved. However, the same ISSN can be used for different file formats of the same online serial; this "media-oriented identification" of serials made sense in the 1970s. In the 1990s and onward, with personal computers, better screens, the Web, it makes sense to consider only content, independent of media; this "content-oriented identification" of serials was a repressed demand during a decade, but no ISSN update or initiative occurred. A natural extension for ISSN, the unique-identification of the articles in the serials, was the main demand application. An alternative serials' contents model arrived with the indecs Content Model and its application, the digital object identifier, as ISSN-independent initiative, consolidated in the 2000s. Only in 2007, ISSN-L was defined in the
Scientific American is an American popular science magazine. Many famous scientists, including Albert Einstein, have contributed articles to it, it is the oldest continuously published monthly magazine in the United States. Scientific American was founded by inventor and publisher Rufus M. Porter in 1845 as a four-page weekly newspaper. Throughout its early years, much emphasis was placed on reports of what was going on at the U. S. Patent Office, it reported on a broad range of inventions including perpetual motion machines, an 1860 device for buoying vessels by Abraham Lincoln, the universal joint which now can be found in nearly every automobile manufactured. Current issues include a "this date in history" section, featuring excerpts from articles published 50, 100, 150 years earlier. Topics include humorous incidents, wrong-headed theories, noteworthy advances in the history of science and technology. Porter sold the publication to Alfred Ely Beach and Orson Desaix Munn a mere ten months after founding it.
Until 1948, it remained owned by Company. Under Munn's grandson, Orson Desaix Munn III, it had evolved into something of a "workbench" publication, similar to the twentieth-century incarnation of Popular Science. In the years after World War II, the magazine fell into decline. In 1948, three partners who were planning on starting a new popular science magazine, to be called The Sciences, purchased the assets of the old Scientific American instead and put its name on the designs they had created for their new magazine, thus the partners—publisher Gerard Piel, editor Dennis Flanagan, general manager Donald H. Miller, Jr.—essentially created a new magazine. Miller retired in 1979, Flanagan and Piel in 1984, when Gerard Piel's son Jonathan became president and editor. In 1986, it was sold to the Holtzbrinck group of Germany. In the fall of 2008, Scientific American was put under the control of Nature Publishing Group, a division of Holtzbrinck. Donald Miller died in December 1998, Gerard Piel in September 2004 and Dennis Flanagan in January 2005.
Mariette DiChristina is the current editor-in-chief, after John Rennie stepped down in June 2009. Scientific American published its first foreign edition in 1890, the Spanish-language La America Cientifica. Publication was suspended in 1905, another 63 years would pass before another foreign-language edition appeared: In 1968, an Italian edition, Le Scienze, was launched, a Japanese edition, Nikkei Science, followed three years later. A new Spanish edition, Investigación y Ciencia was launched in Spain in 1976, followed by a French edition, Pour la Science, in France in 1977, a German edition, Spektrum der Wissenschaft, in Germany in 1978. A Russian edition V Mire Nauki was launched in the Soviet Union in 1983, continues in the present-day Russian Federation. Kexue, a simplified Chinese edition launched in 1979, was the first Western magazine published in the People's Republic of China. Founded in Chongqing, the simplified Chinese magazine was transferred to Beijing in 2001. In 2005, a newer edition, Global Science, was published instead of Kexue, which shut down due to financial problems.
A traditional Chinese edition, known as Scientist, was introduced to Taiwan in 2002. The Hungarian edition Tudomány existed between 1984 and 1992. In 1986, an Arabic edition, Oloom Magazine, was published. In 2002, a Portuguese edition was launched in Brazil. Today, Scientific American publishes 18 foreign-language editions around the globe: Arabic, Brazilian Portuguese, Simplified Chinese, Traditional Chinese, Dutch, German, Hebrew, Japanese, Lithuanian, Romanian and Spanish. From 1902 to 1911, Scientific American supervised the publication of the Encyclopedia Americana, which during some of that period was known as The Americana, it styled itself "The Advocate of Industry and Enterprise" and "Journal of Mechanical and other Improvements". On the front page of the first issue was the engraving of "Improved Rail-Road Cars"; the masthead had a commentary as follows: Scientific American published every Thursday morning at No. 11 Spruce Street, New York, No. 16 State Street, No. 2l Arcade Philadelphia, by Rufus Porter.
Each number will be furnished with from two to five original Engravings, many of them elegant, illustrative of New Inventions, Scientific Principles, Curious Works. Improvements and Inventions; this paper is entitled to the patronage of Mechanics and Manufactures, being the only paper in America, devoted to the interest of those classes. As a family newspaper, it will convey more useful intelligence to children and young people, than five times its cost in school instruction. Another important argument in favor of this paper, is that it will be worth two dollars at the end of the year when the volume is complete, (Old volumes of the New York Mechanic, being now worth double th
The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti
The tilde is a grapheme with several uses. The name of the character came into English from Spanish and from Portuguese, which in turn came from the Latin titulus, meaning "title" or "superscription"; the reason for the name was that it was written over a letter as a scribal abbreviation, as a "mark of suspension", shown as a straight line when used with capitals. Thus the used words Anno Domini were abbreviated to Ao Dñi, an elevated terminal with a suspension mark placed over the "n"; such a mark could denote the omission of several letters. This saved on the cost of vellum and ink. Medieval European charters written in Latin are made up of such abbreviated words with suspension marks and other abbreviations; the tilde has since been applied to a number of other uses as a diacritic mark or a character in its own right. These are encoded in Unicode at U+0303 ◌̃ COMBINING TILDE and U+007E ~ TILDE, there are additional similar characters for different roles. In lexicography, the latter kind of tilde and the swung dash are used in dictionaries to indicate the omission of the entry word.
This symbol informally means "approximately", "about", or "around", such as "~30 minutes before", meaning "approximately 30 minutes before". It can mean "similar to", including "of the same order of magnitude as", such as: "x ~ y" meaning that x and y are of the same order of magnitude. Another approximation symbol is the double-tilde ≈, meaning "approximately equal to", the critical difference being the subjective level of accuracy: ≈ indicates a value which can be considered functionally equivalent for a calculation within an acceptable degree of error, whereas ~ is used to indicate a larger significant, degree of error; the tilde is used to indicate "equal to" or "approximately equal to" by placing it over the "=" symbol, like so: ≅. In the computing field in Unix based systems, the tilde indicates the user's home directory; the text of the Domesday Book of 1086, relating for example, to the manor of Molland in Devon, is abbreviated as indicated by numerous tildes. The text with abbreviations expanded is as follows: Mollande tempore regis Edwardi geldabat pro quattuor hidis et uno ferling.
Terra est quadraginta carucae. In dominio sunt tres carucae et decem servi et triginta villani et viginta bordarii cum sedecim carucis. Ibi duodecim acrae prati et quindecim acrae silvae. Pastura tres leugae in longitudine et latitudine. Libras ad pensam. Huic manerio est adjuncta Blachepole. Elwardus tenebat tempore regis Edwardi pro manerio et geldabat pro dimidia hida. Terra est duae carucae. Ibi sunt quinque villani cum uno servo. Valet viginti solidos arsuram. Eidem manerio est injuste adjuncta Nimete et valet quindecim solidos. Ipsi manerio pertinet tercius denarius de Hundredis Nortmoltone et Badentone et Brantone et tercium animal pasturae morarum; the incorporation of the tilde into ASCII is a direct result of its appearance as a distinct character on mechanical typewriters in the late nineteenth century. When all character sets were pieces of metal permanently installed, number of characters much more limited than in typography, the question of which languages and markets required which characters was an important one.
Any good typewriter store had a catalog of alternative keyboards that could be specified for machines ordered from the factory. At that time, the tilde was used only in Portuguese typewriters. In Modern Spanish, the tilde is used only with ñ and Ñ. Both were conveniently assigned to a single mechanical typebar, which sacrificed a key, felt to be less important the ½—¼ key. Portuguese, uses not ñ but nh, it uses the tilde on the vowels a and o. So as not to sacrifice two of the limited keys to ã Ã õ Õ, the decision was made to make the ~ a separate "dead" character in which the carriage holding the paper did not move. Dead keys, which had a notch cut out to avoid hitting a mechanical linkage that triggered carriage movement, were used for characters that were intended to be combined. On mechanical typewriters, Spanish keyboards had a dead key, which contained the acute accent, used over any vowel, the dieresis, used only over u, it was a simple matter to create a dead key for a Portuguese keyboard to be overstruck with a and o and so the ~ was born as a typographical character, which did not exist as a type or hot-lead printing character.
That was a product of the first and leading manufacturer of typewriters, Remington. As indicated by the etymological origin of the word "tilde" in English, this symbol has been associated with the Spanish language; the connection stems from the use of the tilde above the letter "n" to form "ñ" in Spanish, a feature shared by only a few other languages, all connected to Spanish. This peculiarity can help non-native speakers identify a text as being written in Spanish with little chance of error. In addition, most native speakers, although not all, use the word "español" to refer to their language. During the 1990s, Spanish-speaking intellectuals and news outlets demonstrated support for the language and the culture by defending this letter against globalisation and computerisation trends that threatened to remove it from keyboards and other standardised products and codes; the Instituto Cervantes, founded by Spain's government to promote the Spanish language internationally, chose as its logo a stylised Ñ with a large tilde.
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The term phonation has different meanings depending on the subfield of phonetics. Among some phoneticians, phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration; this is the definition used among those who study laryngeal anatomy and physiology and speech production in general. Phoneticians in other subfields, such as linguistic phonetics, call this process voicing, use the term phonation to refer to any oscillatory state of any part of the larynx that modifies the airstream, of which voicing is just one example. Voiceless and supra-glottal phonations are included under this definition; the phonatory process, or voicing, occurs when air is expelled from the lungs through the glottis, creating a pressure drop across the larynx. When this drop becomes sufficiently large, the vocal folds start to oscillate; the minimum pressure drop required to achieve phonation is called the phonation threshold pressure, for humans with normal vocal folds, it is 2–3 cm H2O.
The motion of the vocal folds during oscillation is lateral, though there is some superior component as well. However, there is no motion along the length of the vocal folds; the oscillation of the vocal folds serves to modulate the pressure and flow of the air through the larynx, this modulated airflow is the main component of the sound of most voiced phones. The sound that the larynx produces is a harmonic series. In other words, it consists of a fundamental tone accompanied by harmonic overtones, which are multiples of the fundamental frequency. According to the source–filter theory, the resulting sound excites the resonance chamber, the vocal tract to produce the individual speech sounds; the vocal folds will not oscillate if they are not sufficiently close to one another, are not under sufficient tension or under too much tension, or if the pressure drop across the larynx is not sufficiently large. In linguistics, a phone is called voiceless. In speech, voiceless phones are associated with vocal folds that are elongated tensed, placed laterally when compared to vocal folds during phonation.
Fundamental frequency, the main acoustic cue for the percept pitch, can be varied through a variety of means. Large scale changes are accomplished by increasing the tension in the vocal folds through contraction of the cricothyroid muscle. Smaller changes in tension can be effected by contraction of the thyroarytenoid muscle or changes in the relative position of the thyroid and cricoid cartilages, as may occur when the larynx is lowered or raised, either volitionally or through movement of the tongue to which the larynx is attached via the hyoid bone. In addition to tension changes, fundamental frequency is affected by the pressure drop across the larynx, affected by the pressure in the lungs, will vary with the distance between the vocal folds. Variation in fundamental frequency is used linguistically to produce tone. There are two main theories as to how vibration of the vocal folds is initiated: the myoelastic theory and the aerodynamic theory; these two theories are not in contention with one another and it is quite possible that both theories are true and operating to initiate and maintain vibration.
A third theory, the neurochronaxic theory, was in considerable vogue in the 1950s, but has since been discredited. The myoelastic theory states that when the vocal cords are brought together and breath pressure is applied to them, the cords remain closed until the pressure beneath them, the subglottic pressure, is sufficient to push them apart, allowing air to escape and reducing the pressure enough for the muscle tension recoil to pull the folds back together again; the pressure builds up once again until the cords are pushed apart, the whole cycle keeps repeating itself. The rate at which the cords open and close, the number of cycles per second, determines the pitch of the phonation; the aerodynamic theory is based on the Bernoulli energy law in fluids. The theory states that when a stream of breath is flowing through the glottis while the arytenoid cartilages are held together, a push-pull effect is created on the vocal fold tissues that maintains self-sustained oscillation; the push occurs during glottal opening, when the glottis is convergent, the pull occurs during glottal closing, when the glottis is divergent.
Such an effect causes a transfer of energy from the airflow to the vocal fold tissues which overcomes losses by dissipation and sustain the oscillation. The amount of lung pressure needed to begin phonation is defined by Titze as the oscillation threshold pressure. During glottal closure, the air flow is cut off until breath pressure pushes the folds apart and the flow starts up again, causing the cycles to repeat; the textbook entitled Myoelastic Aerodynamic Theory of Phonation by Ingo Titze credits Janwillem van den Berg as the originator of the theory and provides detailed mathematical development of the theory. This theory states that the frequency of the vocal fold vibration is determined by the chronaxie of the recurrent nerve, not by breath pressure or muscular tension. Advocates of this theory thought that every single vibration of the vocal folds was due to an impulse from the recurrent laryngeal nerves and that the acoustic center in the brain regulated the speed of vocal fold vibration.
Speech and voice scientists have long since left this theory as the muscles have been shown to not be able to contract fast enough to accomplish the vibration. In addition, persons with paralyzed vocal folds can produce phonation, whic
A diacritic – diacritical mark, diacritical point, diacritical sign, or accent – is a glyph added to a letter, or basic glyph. The term derives from the Ancient Greek διακριτικός, from διακρίνω. Diacritic is an adjective, though sometimes used as a noun, whereas diacritical is only an adjective; some diacritical marks, such as the acute and grave, are called accents. Diacritical marks may appear above or below a letter, or in some other position such as within the letter or between two letters; the main use of diacritical marks in the Latin script is to change the sound-values of the letters to which they are added. Examples are the diaereses in the borrowed French words naïve and Noël, which show that the vowel with the diaeresis mark is pronounced separately from the preceding vowel. In other Latin-script alphabets, they may distinguish between homonyms, such as the French là versus la that are both pronounced /la/. In Gaelic type, a dot over a consonant indicates lenition of the consonant in question.
In other alphabetic systems, diacritical marks may perform other functions. Vowel pointing systems, namely the Arabic harakat and the Hebrew niqqud systems, indicate vowels that are not conveyed by the basic alphabet; the Indic virama and the Arabic sukūn mark the absence of vowels. Cantillation marks indicate prosody. Other uses include the Early Cyrillic titlo stroke and the Hebrew gershayim, which mark abbreviations or acronyms, Greek diacritical marks, which showed that letters of the alphabet were being used as numerals. In the Hanyu Pinyin official romanization system for Chinese, diacritics are used to mark the tones of the syllables in which the marked vowels occur. In orthography and collation, a letter modified by a diacritic may be treated either as a new, distinct letter or as a letter–diacritic combination; this varies from language to language, may vary from case to case within a language. English is the only major modern European language requiring no diacritics for native words.
In some cases, letters are used as "in-line diacritics", with the same function as ancillary glyphs, in that they modify the sound of the letter preceding them, as in the case of the "h" in the English pronunciation of "sh" and "th". Among the types of diacritic used in alphabets based on the Latin script are: accents ◌́ – acute ◌̀ – grave ◌̂ – circumflex ◌̌ – caron, wedge ◌̋ – double acute ◌̏ – double grave ◌̃ - tilde dots ◌̇ – overdot ◌̣ – an underdot is used in Rheinische Dokumenta and in Hebrew and Arabic transcription ◌·◌ – interpunct tittle, the superscript dot of the modern lowercase Latin i and j ◌̈ – diaeresis or umlaut ◌ː – triangular colon, used in the IPA to mark long vowels. Curves ◌̆ – breve ◌̑ - inverted breve ◌͗ – sicilicus, a palaeographic diacritic similar to a caron or breve ◌̃ – tilde ◌҃ – titlo vertical stroke ◌̩ – syllabic a subscript vertical stroke is used in IPA to mark syllabicity and in Rheinische Dokumenta to mark a schwa macron or horizontal line ◌̄ – macron ◌̱ – underbar overlays ◌⃓ – vertical bar through the character ◌̷ – slash through the character ◌̵ – crossbar through the character ring ◌̊ – overring superscript curls ◌̓ – apostrophe ◌̉ – hoi ◌̛ – horn subscript curls ◌̦ – undercomma ◌̧ – cedilla ◌̡ ◌̢ – hook, left or right, sometimes superscript ◌̨ – ogonek double marks ◌͝◌ – double breve ◌͡◌ – tie bar or top ligature ◌᷍◌ – double circumflex ◌͞◌ – longum ◌͠◌ – double tilde double sub/superscript diacritics ◌̧ ̧ - double cedilla ◌̨ ̨ - double ogonek ◌̈ ̈ - double diaeresisThe tilde, comma, apostrophe and colon are sometimes diacritical marks, but have other uses.
Not all diacritics occur adjacent to the letter. In the Wali language of Ghana, for example, an apostrophe indicates a change of vowel quality, but occurs at the beginning of the word, as in the dialects ’Bulengee and ’Dolimi; because of vowel harmony, all vowels in a word are affected, so the scope of the diacritic is the entire word. In abugida scripts, like those used to write Hindi and Thai, diacritics indicate vowels, may occur above, before, after, or around the consonant letter they modify; the tittle on the letter i of the Latin alphabet originated as a diacritic to distinguish i from the minims of adjacent letters. It first appeared in the 11th century in the sequence ii spread to i adjacent to m, n, u, to all lowercase i's; the j a variant of i, inherited the tittle. The shape of the diacritic developed from resembling today's acute accent to a long flourish by the 15th century. With the advent of Roman type it was reduced to the round. Hamza: indicates a glottal stop. Tanwīn symbols: Serve a grammatical role in Arabic.
The sign ـً is most written in combination with alif, e.g. ـًا. Shadda: Gemination of consonants. Waṣla: Comes most at the beginning of a word. Indicates a type of hamza, pronounced only when the letter is read at the beginnin