Speech Sound Production and Classification

Producing Speech Sounds

Speech sounds are made in three main steps:

1. Breathing Out: First, you push air out of your lungs. This air is the power source for making sounds.
2. Voice Box (Phonation): Next, the air goes through your voice box (larynx). Your vocal cords inside your voice box might vibrate, which creates 'voicing' (the sound of your voice).
3. Shaping Sounds (Articulation): Finally, you use your mouth, jaw, lips, teeth, and tongue to shape the sound from your voice box into actual speech sounds like 'p' or 'a'.

Sorting Speech Sounds

Speech sounds are sorted into groups based on two main things:

• How you make them: This means how your mouth parts move and how open or closed your throat is.
• Their sound qualities: This looks at the sound waves themselves. The most important quality here is called sonority.

Understanding Sonority

Sonority is about how much sound energy a sound has. Think of it like how 'loud' a sound is, but it's more than just loudness. It's connected to:

• How much air flows: Sounds made with a lot of air coming out of your lungs usually have higher sonority.
• Vocal cords vibrating (Voicing): Sounds where your vocal cords vibrate (like 'mmm') have higher sonority. Sounds with less air or no vocal cord vibration (like 'sss') have lower sonority.

Main Types of Sounds

When we put together how sounds are made and their sonority, we get three main types of sounds:

Vowels

Vowels are special because:

• Open mouth/throat: You make them with your mouth and throat fairly open, so air can flow out easily without getting blocked.
• Vocal cords vibrate: Usually, your vocal cords vibrate when you make vowels, so they are 'voiced' sounds.
• Loud and clear sound: Because your mouth is open and your vocal cords vibrate, vowels have a lot of sound energy and are very sonorous.
• Can be held long: You can hold vowel sounds for a long time, like when you sing 'Ah', 'ee', 'oh'.

Glides (Semivowels)

Glides (sometimes called semivowels) are a mix, sharing traits of both vowels and consonants:

• Open mouth/throat (like vowels): Just like vowels, you make glides with an open mouth and throat.
• Shorter and less clear (like consonants): But they are shorter and have less sound energy than regular vowels.
• Quick, moving sounds: They often act as quick connecting sounds, moving fast from one vowel-like position to another.
• We'll learn more about glides when we look at vowels in more detail.

Consonants

Consonants are different from vowels in a few ways:

• Blocked air flow: You make consonants by using your lips, tongue, teeth, etc., to block the air flow in your mouth or throat, either partly or completely.
• Less air: Because of the blockage, less air comes out of your lungs compared to making vowels.
• Less clear sound: This means consonants have less sound energy and are less sonorous than vowels.
• Shorter sound: They are usually shorter than vowel sounds.
• Voiced or unvoiced: Your vocal cords might vibrate (voiced, like 'b') or not vibrate (unvoiced, like 'p') when you make consonants.

Sonority and Word 'Beats' (Syllables)

The idea of sonority (how much sound energy a sound has) is found in all languages. It's how spoken words are basically put together.

What is a Syllable?

Every spoken word has one or more syllables. You can think of a syllable as a 'beat' in a word (like ball has $1$ beat, basket has $2$ beats, bicycle has $3$ beats). In clearer sound terms, a syllable is defined as a:

• Sound peak: It's a central sound that has the most sonority, with less sonorous sounds around it.

Parts of a Syllable

A syllable usually has a vowel or another very sonorous sound at its center; this center part is called the nucleus. Less sonorous sounds, like glides and consonants, come before and after this nucleus.

Examples of Syllable Structure

Let's look at some words to understand this better:

• Word: ball
  • Center sound (nucleus): The clear vowel sound 'ah' ($/ɑ/$ or $/ɔ/$).
  • Less clear sounds: The 'b' ($/b/$) sound comes before, and the 'l' ($/l/$) sound comes after the 'ah'. So, it's 'b-ah-l', with 'ah' being the strongest sound.
• Word: basket
  • First part: Has the vowel sound 'a' ($/æ/$).
  • Second part: Has the vowel sound 'i' ($/ɪ/$).
  • Consonants: The 'b' ($/b/$) comes before the first vowel, 'sk' ($/sk/$) is between the two vowels, and 't' ($/t/$) comes after the second vowel. The vowels are the central 'peaks' in each syllable.
• Word: bicycle
  • (For you to figure out! You'd find the vowel sounds 'ai', 'i', 'uh' as the centers of the syllables, surrounded by 'b', 's', 'k', 'l' consonant sounds).

Important Tip:

What you write (letters) is not always exactly what you say (sounds). One letter can make many sounds, many letters can make one sound, or sometimes a letter makes no sound at all.