Why is phonetics studied?



To us, speaking and listening to speech comes so naturally. Have you ever consciously thought about what processes are involved in this? This is exactly what Phonetics aims to do. It aims to give a “systematic, conscious consideration of how speech sounds are made, what they sound like, and how they compare with each other”.[1]


Phonetics is an important foundation to many areas of linguistics. Think about this. Without the study of Phonetics…

  • How could you study a child’s development in their production and perception of speech sounds? – Child Language Acquisition.
  • How would you be able to understand and treat speech and hearing disorders? – Clinical Phonetics.
  • How would a computer system be able to turn text into speech correctly? – Speech Synthesis.
  • How would a mobile phone be able to recognise what you say to it? – Speech Recognition.
  • And, in a criminal trial, how could you prove whether a voice recording is or isn’t the suspects voice? – Forensic Phonetics.

Clinical Phonetics

Speech and hearing disorders can have a huge impact on somebody’s social life and can also affect them in their career, causing them many financial difficulties. This is where Clinical Phonetics comes into use. In order to help people with their speech and hearing, we need to be able to understand how things work normally. Thus, knowing how speech sounds are produced (Articulatory Phonetics) and how they are perceived (Auditory Phonetics). By knowing what is right, we can recognise what is going wrong and can finally help the person with their speech or hearing disorder! 

First and Second Language Acquisition

Without us consciously realising, Phonetics was a crucial part of learning language earlier on in life, with us babbling on like there was no tomorrow and our ears being as alert as ever. Thanks to Phonetic research being applied to child language acquisition, we now know exactly how proficient a child’s perception of speech sounds is. Did you know that very young babies are able to differentiate between alien speech sounds? Try doing this yourself by listening to a completely unfamiliar language (e.g., on YouTube). This will most likely sound like complete gobbledegook, and it should be quite difficult to differentiate between the sounds. As a matter of fact, it is a skill gradually lost by the age of 12 months, meaning that we no longer have the perceptual aptitude to do this. Therefore, this has been described as a “perceptual narrowing” phenomenon.

Knowing more about the way speech sounds are produced also means we can devise better ways of teaching and learning the oral aspects of foreign languages, in second language acquisition.

Studying the sounds of endangered languages

Endangered languages have been of great interest to both anthropologists and linguists for decades. It can be said that a culture is nothing without its language. The culture’s history, traditions and ways of life are all ingrained into the language, shaping it and unifying its people. So it’s not hard to figure out what happens when this language is no longer spoken. Essentially, it’s culture leaves with it. As minority groups are gradually starting to favour the majority language, more and more people are losing their mother tongue. Exposure to modern day novelties, such as TV, radio and easy modes of transport, means that other languages are becoming more accessible than ever. It is predicted that just under an immense 60% of the world's languages will be lost in a hundred years' time.

So how is this important in Phonetics? Simply, if the language is no longer spoken, then neither are its sounds, meaning they are extremely vulnerable of being completely lost. Ladefoged, an influential academic in this field, has previously said that “the disappearance of a language is a loss of a resource for the scientific study of human speech communication”.[2] Phoneticians strive to document the phonetic structures of these endangered languages before they disappear undiscovered.

Speech Technology

Traces of phonetics can be seen in technology in your everyday lives, from your TV or Radio to your mobile phone or video camera. We are able to make recordings of speech and play them back easily. It is a field that has been growing for decades, and still has amazing potential. Here are some examples of inventions in speech technology.

Speech synthesis 

You may already be familiar with the famous Stephen Hawking and probably know of him due to the way he communicates. He uses a speech synthesiser, which converts what he types into speech. There are two stages to this. The first stage includes a phonetic transcription of the text and its prosody (e.g., intonation, phrasing and duration of sounds). The second is turning this information into sound. However, it isn’t as simple as it sounds. The machine has to factor in that a speech utterance is a continuous stream of sounds, meaning that individual speech sounds should not be produced as they would be in isolation. Instead, they should be produced in terms of the environment within which they are. For example, say the words ‘pill’ and ‘lip’ out loud. If you pay close attention to the /l/ in both words, you will realise that the articulations are subtly different. This is because they are in different contexts within the speech utterance. Therefore, there is no point telling a machine to produce an /l/ (phoneme), but to tell it which type of /l/ (allophone) instead. Phonetic research helps to make this distinction.


Speech recognition

This is speech being recognised by a machine. Nowadays, speech recognition is used extensively and is of huge benefit in many fields, such as healthcare and the military. It can also be found applied to things like video games, robotics, in court and even aerospace. However, variability in speech is a huge hurdle in speech recognition and there are several confounding factors which can affect its accuracy. For example, variations in speech can be caused by accent, age, sex and also health. The YouTube video to the right illustrates how accents can be particularly problematic for speech recognition.

Forensic Phonetics 

This involves Phonetic research and analysis of speech for the court of law. In court cases, sometimes evidence is given in the form of a speech recording which phoneticians are frequently called upon to analyse. Imagine that the prosecutor is claiming that the voice in the recording is that of the defendants. A phonetician would then be required to prove this right of wrong by analysing the articulatory and acoustic properties of the recording, something of which is allegedly as unique as a fingerprint.


[1] Hewlett, N. and Beck, B., (2006). An Introduction to the Science of Phonetics. New Jersey: Lawrence Erlbaum Associates, Inc.

[2] Ladefoged, P., (2006). Preserving the sounds of disappearing languages. [online]. Available at: <http://www.linguistics.ucla.edu/people/ladefoge/Preserving%20sounds.pdf> [Accessed 23.05.2012]

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