6-Theme : Reading rules of Diphthongs Plan What is Phonetics of Consonants

6-Theme : Reading rules of Diphthongs
Plan

1. 
   What is Phonetics of Consonants.
   
2. 
   Which letters are consonants.
   

Consonant, any speech sound, such as that represented by t, g, f, or z, that is characterized by an articulation with a closure or narrowing of the vocal tract such that a complete or partial blockage of the flow of air is produced. Consonants are usually classified according to place of articulation (the location of the stricture made in the vocal tract, such as dental, bilabial, or velar), the manner of articulation (the way in which the obstruction of the airflow is accomplished, as in stops, fricatives, approximants, trills, taps, and laterals), and the presence or absence of voicing, nasalization, aspiration, or other phonation. For example, the sound for s is described as a voiceless alveolar fricative; the sound for m is a voiced bilabial nasal stop. Additional classificatory information may indicate whether the airstream powering the production of the consonant is from the lungs (the pulmonary airstream mechanism) or some other airstream mechanism and whether the flow of air is ingressive or egressive.

The production of consonants may also involve secondary articulations—that is, articulations additional to the place and manner of articulation defining the primary stricture in the vocal tract.
Consonants are produced by pushing air up from the lungs and out through the mouth and/or nose. Airflow is disrupted by obstructions made by various combinations of vocal articulator movements, so that audible friction is produced. 
They are described in terms of (1) voicing, (2) place of articulation and (3) manner of articulation.
Voicing refers to the presence or absence of vocal vibration during speech sound production. In a voiced sound, there is vocal fold vibration and an audible 'buzzing' sound. In an unvoiced sound, there is no vocal fold vibration. 
Compare the first consonant in thimble (represented by /θ/ with the first sound in this (represented by /ð/). Again, try placing your finger and thumb on your throat whilst producing the sound. In thimble the consonant /θ/ is unvoiced because there is an absence of vocal fold vibration. In this, the consonant /ð/ is voiced because there is a presence of vocal fold vibration.
Now take the following pairs of phonemes (you may need to look at your copy of the phonetic alphabet). In each pair, one sound is voiced and one sound is unvoiced. Which is which?

/p/ and /b/

/t/ and /d/
/ʤ/ and /tʃ/
/g/ and /k/
/f/ and /v/
/z/ and /s/
/ʃ/ and /ʒ/
The place of articulation is the physical location in the vocal tract that a phoneme is produced in, and the kinds of articulatory movements that are involved in producing a sound. Here is a diagram of the vocal tract: