Phonetics: The Sounds of Language

 Phonetics is concerned with describing the speech sounds that occur in the languages of the world. We want to know what these sounds are, how they fall into patterns, and how they change in different circumstances. ..The first job of a phonetician is… to try to find out what people are doing when they are talking and when they are listening to speech.

                                                                   Peter Ladefoged, A Course in Phonetics, 1982,^nd Edition

Knowledge of a language includes knowledge of morphemes, words, phrases, and sentences. It also includes knowing what sounds are in the language and how they may be ‘strung’ together to form these meaningful units.  And although there may be some sounds in one language that are not in another, the sounds of all the languages of the world together constitute a limited set of all the sounds that can be produced by the human vocal tract. To describe speech sounds, it is necessary to know what an individual sound is and how each sound differs from all others. It is also necessary to analyze and interpret the physical, psychological, and physiological aspects of speech sounds. Phonetics is the branch of linguistics that studies the sound of human speech- how they are produced, transmitted, and perceived.

Speech sounds can be described at any stage in the chain of events. The study of the physical properties of the sounds themselves is called acoustic phonetics, the study of the way listeners perceive these sounds is called auditory phonetics, and the study of how the vocal tract produces the sounds of language is called  articulatory phonetics.

Articulatory phonetics

This branch of phonetics is concerned with how speech sounds are produced by the vocal organs, like the lungs, vocal cords, tongue, lips, teeth, hard palate, soft palate, nasal passage, etc. Different speech organs behave in different ways to articulate different speech sounds. Articulatory phonetics studies speech organs as well as their movement and contact in the articulation of speech sounds and provides us with a classification of the sounds used in particular languages and/or language in general.

Acoustic Phonetics

Acoustic phonetics studies how speech sounds journey from the speaker’s mouth to the listener’s ears. To clarify, speech sounds articulated by the speaker are transmitted through the air to the listener. Speech is not made up of a series of isolated sounds. Rather, it is a natural process resulting from the production of interrelated sounds conveyed by the speakers to the listeners through the channel, that is, air. The journey of speech sounds from the speakers to the listener is made up in the form of sound waves comprising frequencies and amplitudes. These sound waves are the subject matter of acoustic phonetics. Briefly speaking, this branch of phonetics explores and describes how speech sounds are transmitted from the speaker to the listeners through the ear. This branch of phonetics analyzes the physical properties of speech sounds, that is, frequency (pitch), amplitude (loudness), duration, etc. It uses tools like spectrograms to visualize sound waves.

 Auditory Phonetics

Auditory phonetics studies how the listener receives and realizes speech sounds, i.e., how the ear and brain perceive speech sounds. It involves hearing, auditory processing, and speech perception. To be more specific, speech sounds articulated by the speaker and transmitted through the air are heard and perceived by the listener. And to listen to and realize speech sounds, the listener has to use his/ her ears, the auditory nerve, and the brain. The reception and perception of speech sounds create a complex process. This process is explored, analyzed, and interpreted in auditory phonetics.

 A speaker of English knows that there are three sounds in the word cat, the initial sound represented by the letter c, the second by a, and the final sound by t. Yet physically, the word is just one continuous sound. The ability to analyze a word into its sounds does not depend on knowledge of how the word is spelled. Not and knot have three sounds, even though the first sound in knot is represented by the two letters kn. The printed word psycho has six letters which represent only four sounds- ps, y, ch, o.

It is difficult if not impossible, to segment the sound of someone clearing their throat in to a sequence of discrete units. This is because these sounds are not the sounds of any morpheme in any human language; it is not because it is a single continuous sound. We do not produce one sound, then another, then another when we say the word cat. We move our organs of speech continuously and produce a continuous signal.  

Thus, the way we use our linguistic knowledge to produce meaningful utterances is complicated. It can be viewed as a chain of events starting with an idea or message in the brain or mind of the speaker and ending with a similar message in the brain of the hearer. The message is put into a form that is dictated by the language we are speaking. It must then be transmitted by nerve signals to the organs of speech articulation, which produce different physical sounds.