Phonetics

Phonetics is a branch of linguistics that studies how we make and understand speech sounds. It looks at the way our mouths shape sounds, how those sounds travel through the air, and how our ears and brains receive them. This field is split into three main areas: articulatory phonetics, which looks at how we physically create sounds; acoustic phonetics, which studies the sound waves that travel between us; and auditory phonetics, which examines how we hear and understand these sounds. People who study phonetics are called phoneticians.

Phonetics is important because it helps us understand how different languages work, even sign languages like American Sign Language and Australian Sign Language. While spoken languages such as English use sounds made with the mouth and heard with the ears, sign languages use hand movements seen with the eyes. Some sign languages even have special ways of communicating for people who are both deaf and blind, using hand movements that are both made and felt with the hands, known as tactile signing. This shows how phonetics covers many ways humans communicate.

History

The study of phonetics began a long time ago. Around the 6th century BCE, scholars from Sanskrit started studying how sounds are made. One famous scholar, Pāṇini, wrote about how sounds are produced, like the difference between tones and noises.

Later, in the 1800s, people began studying phonetics more seriously again. They used new tools to record sounds and developed ways to write down speech sounds clearly. This helped teachers, especially those who worked with deaf children, to better understand and teach speech.

Production

Main article: Language production

Language production is how we turn thoughts into spoken or signed words. It starts with choosing words that match what we want to say, called lexical selection. These words carry meaning and grammatical information.

Next, we plan how to say the words using sounds called phonemes. These sounds are made by moving parts of our mouth in specific ways, like closing lips or moving the tongue. Finally, muscles move to create the sounds we hear in speech. This process goes from idea to planned words to sound.

Place of articulation

Sounds we make when speaking are called consonants. They are created by closing parts of our vocal tract, usually the mouth, in different ways. The place where we make these sounds changes what we hear. For example, the "f" in "fought" uses the lips, while the "th" in "thought" uses the tongue.

We can make sounds using different parts of the tongue: the front (coronal), the back (dorsal), or deep in the throat (radical). Each part helps create unique sounds. For instance, English has many sounds made with the front of the tongue, like "s" and "sh."

Acoustics

Speech sounds are created when the airstream is changed by the articulators, such as the tongue and lips, producing different sounds. The way these articulators shape the airstream—how far the tongue is from the roof of the mouth, for example—affects the sound we hear. Words like tack and sack start with similar sounds but differ slightly in tongue position, which changes the sound.

One important feature of speech sounds is whether they are voiced. Voiced sounds are made when the vocal folds in the throat vibrate. This vibration creates a special sound, and many sounds can be made with or without this vibration. For example, some sounds are always voiced, while others can be either voiced or unvoiced depending on how they are made. The way the vocal folds vibrate can also change the pitch or tone of the sound, which is important in some languages for meaning.

Perception

Main article: Speech perception

Language perception is how we understand spoken language. When we hear speech, our brains break down the continuous sound into smaller parts like individual sounds, small word pieces, and whole words. We focus on certain sound features that help us tell these parts apart, even though many details in the sound can vary.

Hearing starts when sound waves enter our ears and make the eardrum vibrate. These vibrations travel through small bones to a spiral-shaped tube in the ear called the cochlea. Inside the cochlea, special cells convert the vibrations into signals that go to the brain. This helps us recognize different pitches and sounds.

Besides individual sounds, phonetics also studies larger parts of speech like syllables and phrases. These have features such as pitch, speed, and loudness that help give meaning and emotion to what we say. Different languages use these features in various ways to show emphasis or tone.

Subdisciplines

Main article: Acoustic phonetics Main article: Articulatory phonetics Main article: Auditory phonetics

Phonetics is the study of speech sounds and how we make, hear, and understand them. There are three main areas of phonetics. Acoustic phonetics looks at the sound waves created when we speak. Articulatory phonetics focuses on how we shape our mouths to create different sounds. Auditory phonetics explores how our ears and brains process these sounds, helping us understand spoken language.

Describing sounds

Human languages use many different sounds, and linguists describe these sounds in ways that work for any language. We can describe sounds by how we move our mouths to make them. For example, we have consonants, which are sounds made by closing or partly closing the mouth, and vowels, which are sounds made without any blockage in the mouth.

We can also describe sounds by how they sound, which is linked to how we make them with our mouths. Tools like the International Phonetic Alphabet help us write down these sounds using special symbols. For sign languages, there are different systems to describe hand shapes and movements.

Sign languages

Unlike spoken languages, sign languages are understood with the eyes instead of the ears. Signs are made using the hands, upper body, and head, with the hands and arms being the main parts used. Movements closer to the body are called proximal, while movements further away are distal. Signs near the face allow for very small differences in finger movement to be seen.

Sign languages use both hands, and signers can choose which hand to use without problems. When both hands are used, they often move in the same way, known as the Symmetry Condition. One hand may stay still while the other moves, following the Dominance Condition. Sometimes, one hand may be dropped during casual conversations. Just like in spoken languages, signs can influence each other, such as making handshapes more similar to nearby signs.

Main article: Sign language