VOWEL CATEGORY COMPACTNESS
(Phonetics) We obtained the compactness of each vowel category in the F1–F2 vowel space in two steps.

1. The F1 and F2 (Hz) of all vowel tokens were fitted to a customised MatLab script (Kartushina and Frauenfelder 2014), which calculated the area of an ellipse (Hz²) for each vowel category, participant, and register (ellipse_area).
2. For the sake of clarity and ease of interpretability, the largest ellipse in the sample was then used as a reference point (max_ellipse_area), and the vowel category compactness was computed as a ratio score against the reference point for each participant, category and register with the formula:

   vowel category compactness = max_ellipse_area ÷ ellipse_area

VOWEL CATEGORY DISTINCTIVENESS
(Phonetics) We measured how distinct participants' vowel categories were from each other in the F1–F2 vowel space. "Vowel category distinctiveness" was computed as the between-vowel category Sum of Squares (the squared distances of category cluster centroids from the overall vowel space centroid) divided by the total Sum of Squares (squared distances of individual vowel tokens from the overall vowel space centroid), for each participant and register, for eight vowel categories (we omitted the category /y/, as it fully overlaps with the Norwegian /i/ in the F1–F2 space, as the distinguishing feature is F3). Thus, vowel category distinctiveness can be thought of as a clustering performance quotient, indexing the proportion of variance in F1 and F2 explained by the vowel category identity, ranging from 0 (cluster/category membership explains no variance) to 1 (cluster/category membership explains all variance). | Audun Rosslund, Julien Mayor, Gabriella Óturai, et al., 2021

VOWEL HARMONY
(Phonology) Assimilation of all vowels in a word to a subsegmental feature like [±back] or [±round]. Applies to all words in a language. Ignores consonants.
 On the surface:

1. All vowels have the same feature value.
2. Or, opaque, with blocking vowels.
3. Or, transparent, where the vowels require the harmonic feature value on both sides.
   a. Example
    [+back] [-back] [-back] [+back]

VOWEL HIATUS

1. (Phonology) The term vowel hiatus is commonly used to refer to a sequence of adjacent vowels belonging to separate syllables. | Roderic F. Casali, 2011
2. (Phonology) Many languages do not tolerate vowel hiatus. Where hiatus would arise in such languages through morphological or syntactic concatenation, it is typically eliminated. One very common means of resolving hiatus is to elide one of the adjacent vowels. In Etsako (Niger-Congo; Nigeria), for example, a word-final vowel is often elided before a following word-initial vowel, as in (1) (data from Elimelech 1976).
   1. a.
       
      b.
       
      c.
       
      d.
       

      /dɛ
      buy
      /ukpo
      cloth
      /owa
      house
      /umhele
      salt

      akpa/
      cup
      ɛnodɛ/
      yesterday
      ɔda/
      different
      ɔtsomhi/
      some

      →
       
      →
       
      →
       
      →
       

      [dakpa]
       
      [ukpɛnodɛ]
       
      [owɔda]
       
      [umhelɔtsomhi]
       

      'buy a cup'
       
      'yesterday's cloth'
       
      'a different house'
       
      'some salt'
       
   
    Although elision of the first of two adjacent vowels is more common cross-linguistically, elision of the second vowel is also attested. | Roderic F. Casali, 1997
3. (Phonology) Or, diaeresis (/daɪˈɛrəsəs, -ˈɪər-/) or dieresis. Describes the occurrence of two separate vowel sounds in adjacent syllables with no intervening consonant. When two vowel sounds instead occur together as part of a single syllable, the result is called a diphthong.
    Some languages do not have diphthongs, except sometimes in rapid speech, or they have a limited number of diphthongs but also numerous vowel sequences that cannot form diphthongs and so appear in hiatus. That is the case for Nuosu, Bantu languages like Swahili, and Lakota. An example is Swahili eua 'purify' with three syllables.
    Many languages disallow or restrict hiatus and avoid it by deleting or assimilating the vowel sound or by adding an extra consonant sound. | Wikipedia, 2025
4. (Example) When two identical vowels meet in hiatus, one is deleted (Leslau 1995). Word-final -ä is generally truncated on allä, especially when encliticized (Leslau 1995).
   Amharic (Afro-Asiatic; Ethiopia)
   1. a. Underlying Form: sabrä-^w-allä-ä
      b. Vowel Hiatus Resolution: sabrä-^w-allä
      c. Truncation: sabrä-^w-all
   
    | Matt Hewett and Ruth Kramer, 2024

VOWEL INHERENT SPECTRAL CHANGE

1. (Phonetics) It has been traditional in phonetic research to characterize monophthongs using a set of static formant frequencies, i.e., formant frequencies taken from a single time-point in the vowel or averaged over the time-course of the vowel. However, over the last twenty years a growing body of research has demonstrated that, at least for a number of dialects of North American English, vowels which are traditionally described as monophthongs often have substantial spectral change. Vowel inherent spectral change has been observed in speakers' productions and has also been found to have a substantial effect on listeners perception. In terms of acoustics, the traditional categorical distinction between monophthongs and diphthongs can be replaced by a gradient description of dynamic spectral patterns. | Geoffrey Stewart Morrison and Peter F. Assmann, 2015
2. (Phonetics) Nearey and Assmann (1986) coined the term vowel inherent spectral change to refer to change in spectral properties inherent to the phonetic specification of vowels. Although such change includes the relatively large formant changes associated with acknowledged diphthongs, the term was explicitly intended to include reliable (but possibly more subtle) spectral change associated with vowel categories of North American English typically regarded as monophthongs. | Terrance M. Nearey, 2012
3. (Example)
    ○ While it has long been established that diphthongs are characterized by changing formant frequencies over time, there is a growing volume of research that shows traditional monophthongs in English may be diphthongized in the sense that they too show vowel inherent spectral changes (VISC; Nearey and Assmann 1986, Hillenbrand et al. 1995). This VISC has been shown to be essential in vowel identification and discrimination.
    Three hypotheses of how VISC is detected by listeners have been proposed (Nearey and Assmann, 1986, Gottfried et al. 1993, Morrison and Nearey 2007). All three are in agreement that the initial formant frequency is important in identifying vowels, but they differ in what other information is necessary.
   1. The onset-offset hypothesis suggests that formant frequencies at the beginning and the end of the vowel are the important spectral properties in perception.
   2. The slope hypothesis claims that perceptual cues are based on the rate of change over time for the formant frequencies irrespective of offset frequencies.
   3. Similar to the slope hypothesis, the direction hypothesis suggests that the direction of formant movement is the relevant piece of information irrespective of vowel duration.
   
    | Kathleen Chiddenton and Michael Kiefte, 2013

VOWEL REDUCTION
(Phonetics) Any of various changes in the acoustic quality of vowels as a result of changes in stress, sonority, duration, loudness, articulation, or position in the word, and which are perceived as "weakening". It most often makes the vowels shorter as well.
 Vowels which have undergone "vowel reduction" may be called reduced or weak. In contrast, an unreduced vowel may be described as full or strong. | Wikipedia, 2022

VP ELLIPSIS

1. (Syntax) The name given to instances of anaphora in which a missing predicate, like that marked by "Δ" in (1b), is able to find an antecedent in the surrounding discourse, as (1b) does in the bracketed material of (1a).
   1. a. Holly Golightly won't [ eat rutabagas ].
      b. I don't think Fred will Δ, either.
    | Kyle Johnson, 2001
2. (Syntax) VPE refers to the phenomenon whereby the main predicate of a clause—typically in combination with its internal arguments—is missing. Two representative examples:
   1. John is sleeping, and Bill is __ too.
   2. Shorty couldn't see Rihanna, but I could __.
    The second conjunct in these sentences is interpreted as 'Bill is sleeping too' and 'I could see Rihanna', respectively, even though the strings sleeping and see Rihanna are not overtly expressed. VPE has garnered the interest of generative syntacticians from the very early days and has dominated the research on ellipsis for several decades. Key publications include Sag (1976), Hankamer and Sag (1976), Williams (1977), Zagona (1982), Hardt (1993), Fiengo and May (1994), Lobeck (1995), Kennedy (1994/2008), and Johnson (2001). | Jeroen van Craenenbroeck, 2014
3. (Syntax) Typically involves non-pronunciation of the verb phrase. This phenomenon, which has already been widely discussed for English in the literature, is illustrated in (1). The second conjunct of this sentence is interpreted as "... and Peter was hassled by the police, too", but the verb phrase is omitted because there is a salient antecedent in the first conjunct that renders the verb phrase in the second conjunct recoverable for the hearer (in fact, repetition of the full verb phrase often feels redundant).
   1. Betsy was hassled by the police, and Peter was, too.
    | L. Aelbrecht and W. Harwood, 2015
4. (Syntax) A constituent containing the main predicate of a clause can go unpronounced, as in Mary will leave before John will [ – ], when certain syntactic, semantic, and discourse conditions are met. This process has come to be known as "VP Ellipsis" (VPE), but this term is misleading: it implies that non-verbal predicates cannot be omitted in the same fashion (they can be), and that VP is the constituent undergoing the operation in question elsewhere (it isn't). | Craig William Turnbull-Sailor, 2014

VP RECYCLING HYPOTHESIS
(Syntax) Five acceptability judgment experiments supported a "VP recycling hypothesis," which claims that when a syntactically-matching antecedent is not available, the listener/reader creates one using the materials at hand.
 We claim that the grammatical resolution of an elided verb phrase requires the presence of a syntactically parallel antecedent. However, in the absence of such an antecedent, the processor may recycle materials at hand and create a suitable syntactic structure (see Tanenhaus, Carlson, and Seidenberg 1985 for a similar hypothesis). We consider recycling to be a performance repair strategy for a structure that is, strictly speaking, ungrammatical. As such, it carries with it varying degrees of difficulty, and results in different levels of acceptability.
 According to the recycling hypothesis, the construction of a verb phrase antecedent depends on grammatical properties of the input and the recycling process follows paths that are made available by grammar. The acceptability of the outcome will depend on the steps needed to create a suitable antecedent. It should be relatively easy to create an antecedent if only one or a small number of grammatically defined operations must be performed on the actual verb phrase to create a verb phrase of the appropriate syntactic shape. If there is clear evidence concerning these operations or concerning the shape of the target verb phrase, then the recycling should be easy and the examples should be judged acceptable, at least relative to examples requiring more operations or examples where less evidence points to the need for these operations. On the other hand, if the processor does not have adequate material to work with in creating the target verb phrase antecedent, then the example should be relatively unacceptable. In particular, if the actual antecedent does not even contain the verb required to head the antecedent verb phrase, the creation of an appropriate verb phrase should be expected to fail and the example should be judged to be unacceptable.
 The VP-recycling hypothesis predicts that finding an antecedent should be easier if the antecedent of the verb phrase ellipsis has the canonical properties of a verb phrase, i.e., it looks like a verb phrase and it occupies a position (e.g., post-subject) that is characteristic of verb phrases. | Ana Arregui, Charles Clifton Jr, Lyn Frazier, and Keir Moulton, 2006

WEAK HIGHER-ORDER ABSTRACT SYNTAX
WHOAS tries to solve the problems of HOAS by turning the negative occurrences of the type of terms in the definition of a data-type into a parameter. In the case of the λ-calculus, the abstraction operator has type:

abs : (Var → Λ) → Λ.

Page Last Modified September 17, 2025

 

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