Phonetics — Speech Sounds

PHONETICS is the study of speech SOUNDS. Linguists describe them precisely using the INTERNATIONAL PHONETIC ALPHABET (IPA) — a special alphabet where each symbol represents EXACTLY ONE sound. So [t] is the t in "top," [θ] is the th in "thin," [ð] is the th in "this." Different languages have different sound inventories.

How sounds are made. Speech sounds are produced by the VOCAL TRACT — lungs push air, vocal cords vibrate (or do not), and the tongue, teeth, and lips shape the airstream. CONSONANTS involve obstructing airflow somewhere. VOWELS are open and continuous. Place of articulation (where the obstruction is — lips, teeth, palate) and manner of articulation (how — stop, fricative, etc.) classify consonants. Vowels are described by tongue position (high/low, front/back) and lip rounding.

Phonetic surprises. Some sounds in OTHER languages do not exist in English: clicks in Xhosa, tones in Mandarin (same syllable, different pitch = different word), implosives in Hausa. Conversely, some English sounds are rare globally (e.g., the th sounds). Each language picks a small subset from possible human sounds. Babies can hear all sounds; by ~1 year, they specialize in their native language's sounds.

Phonetics is one of linguistics' most precise subfields. Once you can describe sounds, you can analyze any language — including the ones you speak without thinking.