Speech Sound Production and Classification
Understanding Speech Sounds: Phonetics and Phonology
The Role of the Larynx and Pharynx in Speech
The larynx is situated at the upper extreme of the trachea (windpipe), sheltered by a group of bones and cartilages that can be seen prominently as the “Adam’s apple.” It has two basic functions: a biological one, preventing food or other objects from entering the trachea, and another related to speech production, controlling the passing of the air.
The pharynx is the cavity comprised between the larynx and the area at the back of the tongue. Its main function is to modulate the acoustic properties of the sounds after passing through the larynx. It is also responsible for what is commonly called the “quality” of the voice (deep or high) and can be enlarged or shortened to modify this quality.
Areas of Phonology
Articulatory phonology is about two phases:
- Mental: Categorization
- Physiological: Production
Auditory phonology involves perceiving and understanding sounds:
- Physiological
- Mental
Acoustic phonology studies sound waves, which are different ways in the air pressure between your mouth and ear. There are three parameters:
- Frequency of vibration of the vocal folds per second.
- Amplitude of vibration.
- Duration
Examples of Phonetic Phenomena
/t/ in “pitbull”: Since we have a consonant cluster involving a sequence of plosive + plosive, in the articulation of the first one /t/, the third stage (the “explosive”) is missing. The organs maintain the closure for the first plosive /t/ with no release until the closure of the second plosive /b/ has been made. In this way, when the organs separate, the only explosion we hear is that of the second plosive.
/t/ in “later” (American English): In general American English, intervocalic /t/, both within words and in linking words, is substituted by a flap or tap, in which the tip of the tongue touches the alveolar ridge once. (e.g., “later,” “get out”).
‘r’ in British vs. American English: In British English, ‘r’ is represented by ‘r’ or ‘rr’ only before a vowel (e.g., “arrive”) and never after a vowel. In American English, on the contrary, ‘r’ is pronounced in all positions, including final ones. Between vowels, it gets weakened and becomes a flap or tap (the tip of the tongue touches the alveolar ridge), similar to the Spanish ‘r’ in “pero”.
Vowel Classification
Vowels are classified in terms of four variables:
Soft palate: All vowel sounds are phonemically oral. Only in certain contexts is the passage to the nasal cavity slightly open, giving them a certain nasal quality.
Jaws: Depending on the degree of separation between the lower and upper jaw, vowels can be classified as:
- Wide: /a:/
- Medium to wide: /æ/, /ɒ/
- Medium: /e/, /ʌ/
- Narrow to medium: /i:/, /ɪ/, /u:/
- Narrow: /ɜ:/, /ə/
Lips: When describing lip position, vowels can be:
- Neutral: /ɪ/, /e/, /æ/, /ɜ:/, /ə/
- Spread: /i:/
- Open: /a:/
- Rounded: /ɒ/, /ɔ:/, /ʊ/
- Protruded: /u:/
Tongue: According to tongue position, vowels can be tense (if reaching a fairly far point in the oral cavity is required, e.g., /i:/, /a:/, /u:/) or lax (/ɪ/, /e/, /æ/, /ɒ/, /ɔ:/, /ʊ/, /ɜ:/, /ə/).
Vowels can also be classified in terms of a horizontal axis (front, if articulated in an area near the lips; central and back, if articulated at the back of the oral cavity) and a vertical axis (close, if articulated near the top level in the oral cavity; close-mid, close-open, open, if articulated near the bottom of the oral cavity).
Vowel Examples with Their Characteristics
- /ɪ/: Front, close-mid, neutral, lax, narrow to medium
- /e/: Front, close-mid, neutral, lax, medium
- /æ/: Front, open-mid, neutral, lax, medium to wide
- /a:/: Central, open, neutral, partially tense, medium to wide
- /ɒ/: Back, open-mid, rounded, lax, medium to wide
- /ɔ:/: Back, open-mid, rounded, lax, medium to fairly wide
- /u:/: Back, close, protruded, tense, narrow to medium
- /ʌ/: Central, open-mid, neutral, lax, wide
- /ɜ:/: Central, open-mid, neutral, lax, narrow
- /ə/ (schwa): Central, open-mid, neutral, extremely lax, narrow