August 25, 2013

Definition

Nasals (also called nasal stops, nasal occlusives, or nasal continuants) are types of consonant sounds. These are called nasals because during their articulation the airflow escapes through the nasal cavity as there is a complete closure in the oral cavity.

Plosives vs. Nasals

The nasal sounds are produced in exactly the same position in the mouth as the pairs of plosives /p/-/b/, / t/-/d/, and /k/-/g/, consequently some phoneticians call them nasal stops. Like plosives, nasals are produced by blocking the airstream completely in the oral cavity. The difference is that for nasals the air pressure is not allowed to build up behind the closure, rather it is allowed to escape through the nasal cavity by lowering the soft palate (velum). Therefore, with a sharp contrast to plosives, it is possible to take a breath and prolong a nasal sound.

Classification

There are only three nasal consonants in English: /m/, /n/, and /ŋ/. They are generally described on three bases:
(1) Manner of Articulation
The manner of articulation refers to  how the articulators approach to each other to create a closure. It also determines the type and degree of hindrance the airflow meets on its way out affected by the closure. The closure takes different manners for different sounds. For instance, during the articulation of the nasal sounds the following sequence of events occurs:
  • The articulators completely block the oral cavity of air; the soft palate is lowered so that the air can escape through the nasal cavity.
  • During the escape of air through the nasal cavity, the vocal folds are together and vibrate.
  • As the air pressure is released through the nose, there is usually not an audible burst when the oral closure is released.
  • When the nasal sound is finished the oral closure is released, unless this is prevented by the requirements of the next sound.
(2) Place/Point of Articulation
The place of articulator refers to the place or point where the speech organs create a closure by either coming close or near contact. This is the place where the sound is produced. There are three types of closures producing nasal sounds:
  1. Bilabial
  2. Alveolar
  3. Velar
(3) Voicing/Phonation
Voicing refers to whether or not the vocal folds are vibrating. If the vocal folds vibrate during the articulation then a voiced sound is produced. Contrariwise, if the vocal folds do not vibrate then a voiceless sound is produced. Some phoneticians use the terms Lenis and Fortis to describe the voiced and voiceless sounds respectively. In English all nasals are voiced sounds.

All three nasal sounds can be summarized in the following table:

Nasals
/m/
/n/
/
Place/Point of Articulation
bilabial
alveolar
velar
Manner of Articulation
nasal
nasal
nasal
Voicing/Phonation
voiced
(lenis)
voiced
(lenis)
Voiced
(lenis)

Detailed Description of Nasals

/m/-Bilabial Nasal
Place of Articulation: The upper and the lower lips. The position of the articulators for this sound is shown in the following illustration:

Bilabial Nasal


Manner of Articulation: During the articulation of /m/ the two lips are pressed together and a closure is made. The soft palate is lowered; consequently the air then goes up the nasal cavity and passes out through the nose.

Voicing: During the articulation of /m/ the vocal folds vibrate, hence it is a voiced bilabial nasal sound.
Distribution: /m/ can occur initially, medially, and finally, for instance:

Nasal Initial Medial Final
/m/ mat laymen gum
/n/-Alveolar Nasal
Place of Articulation: The tip of the tongue and the alveolar ridge. The position of the articulators for this sound is shown in the following illustration:

Alveolar Nasal


Manner of Articulation: During the articulation of /n/the tip of the tongue touches the alveolar ridge and creates a closure. The air is held behind the closure for a while. The soft palate is lowered; consequently the air then goes up the nasal cavity and passes out through the nose.

Voicing: During the articulation of /n/ the vocal folds vibrate, hence it is a voiced alveolar nasal sound.
Distribution: /n/ can occur initially, medially, and finally, for instance:

Nasal Initial Medial Final
/n/ naive sand gun
/ŋ/- Velar Nasal
Place of Articulation: The back of the tongue and the soft plate. The position of the articulators for this sound is shown in the following illustration:

Velar Nasal


Manner of Articulation: During the articulation the back of the tongue comes near the soft palate and creates a closure. The soft palate is lowered; consequently the air then goes up the nasal cavity and passes out through the nose.

Voicing: During the articulation of /ŋ/ the vocal folds vibrate, hence it is a voiced velar nasal sound.
Distribution: /n/ can occur medially, and finally, for instance:

Nasal Initial Medial Final
/ŋ/
-
ankle bring




References


“Consonants.” SLT Info. 2013. SLTInfo.20 August 2013
<http://www.sltinfo.com/consonants.html>.

Mannell,  Robert.“Articulation of Nasal Stops.” Macquarie University. 2009.
Macquarie University.20 August 2013
<http://clas.mq.edu.au/phonetics/phonetics/consonants/nasal_stops.html>.

Roach, Peter. English Phonetics and Phonology: A self-contained, comprehensive pronunciation course.
3rd ed. Cambridge: CUP, 2000.

Varshney, Dr. R.L.  An Introduction of Linguistics & Phonetics. Dhaka: BOC, n.d. 92-93.

Yule, George. The Study of Language. 2nd ed. Cambridge: CUP, 1996. 46.



August 19, 2013

Definition

Fricatives (also known as spirants, continuants), types of consonant sounds, which are produced by forcing the breath squeeze through a narrow gap with audible friction, hence these are termed fricatives.

Discussion: During the production of fricatives, the articulators are brought nearly close together. But as the closure is not quite complete, the oral cavity is not blocked totally, leaving sufficient opening for the airflow to continue. Due to this close approximation of the articulators, the air coming from the lungs has to pass through a narrow gap with great pace, generating audible friction, which is heard as hissing for a voiceless fricative, and buzzing for a voiced one.

Classification

We have nine fricative sounds in English. Except for /h/, all fricatives come in pairs, that is, accompanied by one voiceless and one voiced variant:

Group
Labio-dental
Dental
Alveolar
Palato-alveolar
Glottal
Fricatives
/f/v/
/θ/ð/
/s/z/
/ʃ/ʒ/
/h/




The above sounds are customarily described on the following bases:
  1. Manner of Articulation: The manner of articulation is concerned with airflow i.e. the paths it takes and the degree to which it is impeded by vocal tract constrictions. In other words, manner of articulation describes how the sound is produced.
  2. Place of Articulation: The place of articulation refers to where the sound is produced.
  3. Voicing/Phonation: Voicing refers to whether or not the vocal folds are vibrating. Some phoneticians use the terms Lenis and Fortis to describe the voiced and voiceless sounds respectively.
Discussion: The following discussion endeavours to describe the fricative consonants on the basis of the above criteria:
/f/v/ - Labio-dental Fricatives:
Place of Articulation: The upper teeth and the lower lip.

Labio-dental Fricatives

Manner of Articulation: The lower lip comes very close to the upper teeth and creates a narrow gap. The air escapes through the narrow gap with audible friction.

Voicing:

Fricatives Voicing Reason
/f/ Voiceless
(Fortis)
Vocal folds do not vibrate while producing voice
/v/ Voiced
(Lenis)
Vocal folds vibrate while producing voice

Distribution: /f/ and /v/ can occur initially, medially and finally.

Fricatives Initial Medial Final
/f/ fast confer deaf
/v/ void bevel dove

/θ/ð/ - Dental Fricatives:
Place of Articulation: The upper and the lower teeth and the tip and the blade of the tongue.

Dental Fricatives

Manner of Articulation: The tip of the tongue touches the lower teeth and the blade touches the edge of the upper teeth. The air escapes through the narrow gap between the tip and the blade of the tongue and the front upper teeth and causes audible friction. However, these sounds could be produced in other manners as well:
  • The tongue tip may come close to the back of the upper teeth.
  • The tip or blade of the tongue may approach or touch the upper teeth.
Voicing:

Fricatives Voicing Reason
/θ/ Voiceless
(Fortis)
Vocal folds do not vibrate while producing voice
/ð/ Voiced
(Lenis)
Vocal folds vibrate while producing voice

Distribution: /θ/and /ð/can occur initially, medially and finally.

Fricatives Initial Medial Final
/θ/ theme ether sheath
/ð/ thus brother breathe

/s/z/ - Alveolar Fricatives:
Place of Articulation: Tip and blade of the tongue and the alveolar ridge.

Alveolar Fricatives

Manner of Articulation: The tip and the blade of the tongue come very close to the alveolar ridge and create a narrow gap. The air passes through the narrow gap with audible friction.

Voicing:

Fricatives Voicing Reason
/s/ Voiceless
(Fortis)
Vocal folds do not vibrate while producing voice
/z/ Voiced
(Lenis)
Vocal folds vibrate while producing voice

Distribution: /s/and /z/can occur initially, medially and finally.

Fricatives Initial Medial Final
/s/ sit beside gas
/z/ zoo dazzle nose

/ʃ/ʒ/ - Palato-alveolar Fricatives:
Place of Articulation: The tip and the blade of the tongue; the alveolar ridge.

Palato-alveolar Fricatives

Manner of Articulation: The air passage is blocked by the above articulators. But in contrast with /s/ and /z/, the tongue is placed further back of the alveolar ridge. The closure is then released slowly and the air escapes with audible friction.

 Voicing:

Fricatives Voicing Reason
/ʃ/ Voiceless
(Fortis)
Vocal folds do not vibrate while producing voice
/ʒ/ Voiced
(Lenis)
Vocal folds vibrate while producing voice

Distribution: /ʃ/ can occur initially, medially and finally. Contrariwise, /ʒ/ occurs only medially.

Fricatives Initial Medial Final
/ʃ/ ship pressure wash
/ʒ/ - Pleasure -

/h/ Glottal Fricative:
Place of Articulation: The glottis.

Glottal Fricative

Manner of Articulation: This sound is produced differently than the other fricatives since it does not involve the tongue or the teeth as articulators. For /h/, the sole articulator is the glottis, which is the opening between the vocal folds. The sound is produced when the air passes through the glottis as it is narrowed. The said opening is narrow enough to create some audible friction in the airstream flowing past the vocal folds.

Voicing:

Fricatives Voicing Reason
/h/ Voiceless
(Fortis)
Vocal folds do not vibrate while producing voice

Distribution: /h/ can occur initially and medially.

Fricative Initial Medial Final
/h/ hen behave -

References

Roach, Peter. English Phonetics and Phonology: A self-contained, comprehensive pronunciation course.
3rd ed. Cambridge: CUP, 2000.

 “Sounds of English: Fricatives.” CALLE. 2013. CALLE. 14 August 2013
<http://calleteach.wordpress.com/2010/01/10/sounds-of-english-fricatives/>.

Varshney, Dr. R.L.  An Introduction of Linguistics & Phonetics. Dhaka: BOC, n.d. 94-98.

Yule, George. The Study of Language. 2nd ed. Cambridge: CUP, 1996. 46.


Random Articles