How Humans Create Sound

This post is the second of a series that examines the linguistics of the Tamil language. In this post we take a closer look at how humans produce speech, classification of sounds and the sounds of Tamil.

Speech is made up of ordered sequences of phonemes. Individual phonemes are produced by changing the positions of the various organs associated with speech thereby modulating the air we exhale. The actual sound that is produced and perceived will depend on the immediate neighbors that surround a phoneme (we will discuss this in more detail in a future post).

How Humans Make Sound

In humans, two sets of organs are used to produce sounds; movable and stationary. The movable organs consist of the vocal chords, jaws, lips, and tongue. The teeth and palate make up the stationary organs. The tongue and palate can each be separated into three distinct areas based on the sounds they produce. The sections of the tongue are the tip (நுனிநா), mid (இடைநா) and back (கடைநா). The palate starts with the alveolum (நுனியண்ணம்), the area behind the teeth, followed by the hard palate (இடையண்ணம்) and ends in the velum (கடையண்ணம்), the softer area at the back.

Sounds are produced when two movable organs or one movable and one stationary organ come into contact each other.
ப in பசு ('pa' in 'pasu') is an example of the former where the upper and lower lip touch each other. நா in நாணம் ('na' in 'naanam') is an example of the latter, where the tip of the tongue touches the back of the teeth. Sounds are further classified as  voiced or unvoiced based on the presence or absence of vocal chord vibrations. This interactive web page shows how the different sounds are created.

Fig 1. Organs involved in speech production

The Alphabet of Sounds

The International Phonetic Alphabet (IPA) is a standard used to express the sounds of all existing languages. It uses the Latin alphabet and some modifiers to represent all the phonemes that exist in the various languages.

Sounds in Tamil

The primary sounds of the Tamil are classified as உயிர் ('uyir' meaning life) and மெய் ('mei' meaning body). Life represents the vowel sounds and body represents the consonants. Vowel sounds are further divided into குறில் ('kuril' meaning short) and நெடில் ('nedil' meaning long). Consonants are further divided into வல்லினம் ('vallinam' meaning strong), மெல்லினம் ('mellinam' meaning soft), and இடையினம் ('idaiyinam' meaning mid). In the chart below the word 'letter' is used interchangeably with 'sound'.

Fig 2. Classification of Sounds in Tamil

Vowels

In A Handbook of the Ordinary Dialect of the Tamil Language Volume 1, G.U.Pope describes the Tamil vowel sounds.

"The vowels are remarkably pure and simple. The most careful attention is necessary in order to catch the sounds".

Vowel sounds are produced when air is exhaled through the mouth without any blockage. The specific vowel sound created is determined by vertical position of the tongue (high, mid, low), the shape of the lips (rounded, unrounded), and the horizontal position of the tongue (front, central, back). In Tamil the vowel sounds are always voiced.

                                   
                                  Fig 3. Origin of Tamil Vowel Sounds

அ, இ, உ, எ and ஒ are the short vowel sounds. Each sound has a longer version which is produced in a similar way but held for a longer duration, ஆ, ஈ, ஊ, ஏ, ஓ. Two additional phonemes exist only in the longer version, ஐ and ஔ. The complete set of vowels in Tamil.

Duration (மாத்திரை)

Duration is measured in a unit called மாத்திரை ('maathirai' meaning meter). This is described in the Tolkappiyam.

கண் இமை நொடி என அவ்வே மாத்திரைநுண்ணிதின் உணர்ந்தோர் கண்ட ஆறே   (தொல் 7)

This describes a meter as the time to blink an eye or snap your fingers. Going back to the previous section, short vowels are sounded for one duration and long vowels for two.

Consonants

Consonants are produced when outflow of air from the lungs is completely or partially blocked. They are classified are hard, soft, and mid (refer Fig 2). The classification is based on the pure consonant (ஒற்று), the letter with the dot (புள்ளி) on top*.

*Consonants are commonly combined with a vowel sound, a form called உயிர்-மெய் ('uyirmei' meaning life-body). The composite consonant takes on the characteristic of the vowel when sounded.

காகம் = க் + ஆ + க் + அ + ம்

Hard Consonants (வல்லினம்)

A sound produced by completely blocking the path of the exhaled air is called a stop (அடைப்பொலி). They are sometimes called plosives (வெடிப்பொலி) because they tend to 'explode' when the stop is released. A sound produced by constricting the path through which air flows is called a fricative (உரசொலி). Stops and fricatives make up the hard consonants.

வல்லினம் 

க் ச் ட் த் ப் ற்

Soft Consonants (மெல்லினம்)

Sounds produced by expelling air through the nose are called nasals (மூக்கொலி). These are the soft consonants and sometimes referred to as liquids.

மெல்லினம் 

ங் ஞ் ண் ந் ம் ன்

Mid Consonants (இடையினம்)

Sounds produced by redirecting exhaled air through one or both sides of the tongue, blocking the direct path, are called lateral sounds (மருங்கொலி). When a sound is produced by strong vibrations of a speech organ (lips, tongue) it is called a trill (ஆடொலி). A sound produced by lightly touching the palate is called a tap (அடியொலி). A few sounds have propertied common to vowel and consonant sound generation. Such sounds are called semi-vowel (அரையுயிர்).

இடையினம்

ய் ர் ல் வ் ள் ழ்

Learning the Sounds

Learning a language becomes simpler if you start with and focus on the sounds instead of the script. This is particularly true in Tamil where subtle differences in sound refer to words unrelated in meaning. Here we look at a simple example.

அலகு (beak or unit)   əl̪ku  
அழகு (beauty)            əɻku

Read through the IPA symbols for the Tamil vowels and consonants and listen to the sounds to understand the distinction between the words above. You can see how the organs of articulation interact with each other here.