• Phonetics is of a general nature; it is interested in all the speech sounds used in all human languages: • how they are produced, how they differ from each other, what phonetic features they possess, how they can be classified, etc. • Phonology, on the other hand, aims to discover how speech sounds in a language form patterns and how these sounds are used to convey meaning in linguistic communication.
• [t] and [d] are thus important sounds in English, because they enable us to distinguish tin and din, tie and die, and many more word pairs. • Similarly, [f] and [d] can be shown to be important units too, because they distinguish between fish and dish, fine and dine and many other pairs.
Phonetics & Phonology
Phonetics: Speech Sounds
• Speech and writing are the two media or substances used by natural languages as vehicles for communication. Many languages in the world today are both written and spoken. • Language is first perceived through its sounds. Thus the study of sounds is of great importance in linguistics. Naturally, linguists are not interested in all sounds; they are concerned only with those sounds that are produced by humans through their speech organs and have a role to play in linguistic communication.
• A phoneme is a phonological unit; it is a unit that is of distinctive value. It is an abstract unit. It is not any particular sound, but rather it is represented or realized by a certain pholophone: different phones which can represent a phoneme in different phonetic environments are called the allophones of the phoneme • Phone(音素）: phonetic unit or segment
• Vowels may be distinguished as front, central, and back according to which part of the tongue is held highest. • i.e. A front vowel is one in the production of which the front part of the tongue maintains the highest position • English consonants can be classified in two ways: one is in terms of manner of articulation and the other is in terms of place of articulation.
• In minimal pairs, we can always identify two ―key‖ sound segments that semantically distinguish one word from the other, the two key sounds are therefore ―contrastive‖ in meaning. They are in contrastive distribution. • The two sounds are functioning in language by distinguishing meaning, because the replacement of one with the other will result in meaning change.
Speech sounds
• These sounds are limited in number. This limited range of sounds which are meaningful in human communication constitute the phonic medium of language, and the individual sounds within this range are the speech sounds（言语语音）.
Classification of English speech sounds
English speech sounds are generally classified into two large categories: • Vowels • Consonants • Note: The essential difference between these two classes is that in the production of the former the airstream meets with no obstruction of any kind in the throat, the nose or the mouth, while in that of the latter it is somehow obstructed.
• For instance, the word tin in English consists of three separate sounds, each of which can be given a symbol in a phonetic transcription, [tin]. If we replace [t] by [d], a different word results: din.
Phonology: Sound Patterns
• Both phonology and phonetics are concerned with the same aspect of language -- the speech sounds. But while both are related to the study of sounds, they differ in their approach and focus.
• For example, when we pronounce the two words peak and speak, we are aware that the sound [p] is pronounced differently. • In the word peak, the [p] sound is pronounced with a strong puff of air stream; but the same stop sound is pronounced slightly differently in the word speak; the puff of air is withheld a little.
These three branches of phonetics
• articulatory phonetics （发音语音学） • it studies the sounds from the speaker's point of view, i.e. How a speaker uses his speech organs to articulate the sounds. • auditory phonetics（听觉语音学） • It looks at the sounds from the hearer's point of view, i.e. How the sounds are perceived by the hearer. • acoustic phonetics（声学语音学） • It studies the way sounds travel by looking at the sound waves, the physical means by which sounds are transmitted through the air from one person to another.
Minimal pairs (最小对立体）
• Phonological analysis relies on the principle that certain sounds cause changes in the meaning of a word.