Phonemes, Vowels, Consonants and Distinctive Features

Phonemes and Distinctive Phonological Features

Phonemes: abstract units in the sound system of a language. A phoneme is the mental image that speakers have; each time a phoneme is realized in speech it may have a different physical sound but changes in phonemes can alter the meaning of a word. Phonemes are typically represented between slashes, e.g., /p/ or /a/.

Sound (phonetic realization): the practical articulation of a phoneme — the actual acoustic and articulatory realization in speech.

Phonetics: the physical science that studies the linguistic articulation of each human speech sound and its acoustic characteristics.

Letter: visual symbols through which phonemes are expressed in written form.

Diphthongs: the union of two vowel phonemes within the same syllable, producing a single, gliding vowel-like sound.

Allophones: the variants that occur in the pronunciation of a given phoneme depending on its position in a word or syllable; they do not change word meaning but are conditioned by context.

Distinctive Features of Vowel Sounds

Location (Place of articulation): vowels are described by where in the mouth they are articulated:

• Front (palatal): articulated toward the front of the mouth — examples: /i/, /e/.
• Central (mid): articulated in the middle of the mouth — example: /a/.
• Back (velar): articulated toward the rear of the mouth — examples: /o/, /u/.

Openness (Height):

• Open (low): e.g., /a/.
• Mid-open (mid): e.g., /e/, /o/.
• Closed (high): e.g., /i/, /u/.

Note: All vowels are typically voiced (they involve vibration of the vocal folds).

Distinctive Features of Consonants

The distinctive features of consonants include place of articulation, manner of articulation, and voicing. Below are common categories and definitions.

Place of Articulation

Bilabial: both lips come together (e.g., /p/, /b/, /m/).

Labiodental: the lower lip approaches or touches the upper teeth (e.g., /f/, /v/).

Interdental: the tongue is positioned between the two rows of teeth (e.g., English /θ/, /ð/).

Dental: the tongue touches the inside of the upper teeth.

Alveolar: the tongue approaches or touches the alveolar ridge (the area just behind the upper front teeth) (e.g., /t/, /d/, /s/, /z/).

Palatal: the tongue touches or approaches the hard palate.

Velar: the back of the tongue touches or approaches the soft palate (velum) (e.g., /k/, /g/).

Uvular: articulated near or at the uvula; for example, some languages have a uvular sound often represented by symbols such as /ʀ/ or /q/.

Modes (Manner) of Articulation

Modes describe how the airstream is modified to produce consonants:

• Occlusive (Stop): the vocal tract is completely closed and the air is released with a small burst (e.g., /p/, /t/, /k/).
• Fricative: the articulators narrow the channel so air passes with friction or rubbing (e.g., /s/, /f/).
• Affricate: a stop followed immediately by a fricative, producing both a closure and friction.
• Trill (vibrating): an articulator (e.g., tongue tip) rapidly strikes another structure, causing vibration (e.g., a rolled /r/).
• Lateral: the airstream flows along the sides of the tongue (e.g., /l/).
• Nasal: part of the airflow is released through the nose (e.g., /m/, /n/).

Voicing and Vocal Fold Vibration

Voicing (vibration of the vocal cords): the vocal folds, located in the larynx, vibrate to add a voiced component (loudness and timbre) to a sound. Consonants can be voiced (vocal folds vibrate) or voiceless (vocal folds do not vibrate).

Liquid Consonants, Sonority, and Clusters

Liquid consonants: lateral and rhotic consonants (such as /l/ and /r/) have greater sonority than many other consonants and can cluster with other consonants.

Sonority: a relative measure of loudness and openness of a sound; vowels are typically most sonorous, followed by liquids and nasals, then obstruents.

Consonant clusters: groups of consonants that can be followed by /l/, /r/, and a vowel in various languages; these sequences are common in syllable structure and affect phonotactics.