Consonants and Coarticulation

Overview of Speech Sounds

  • Consonants vs. Vowels

  • Consonants: Produced with constriction or obstruction in the oral cavity.

    • Can be voiced (using vocal folds) or voiceless (using turbulent airflow).

  • Vowels: Produced with an open vocal tract, resonating with more intensity and louder than consonants.

  • Spectral Differences

  • Vowels have lower frequency ranges while consonants have higher frequency sounds.

Types of Consonants

  • Manner of Articulation

  • Stops: Complete closure followed by a burst of air.

  • Fricatives: Narrow opening causing turbulent airflow.

  • Affricates: Combination of stops and fricatives.

  • Nasal Sounds: Air flow through the nasal cavity, always voiced (e.g., /m/, /n/, /ŋ/).

  • Glides and Liquids: More open sounds, similar to vowels (e.g., /w/, /j/, /l/, /r/).

  • Place of Articulation

  • Bilabial: Both lips (e.g., /b/, /p/)

  • Labiodental: Lips and teeth (e.g., /f/, /v/)

  • Dental: Tongue against teeth (e.g., /θ/, /ð/)

  • Alveolar: Tongue against alveolar ridge (e.g., /t/, /d/)

  • Palatal: Tongue against hard palate (e.g., /ʃ/, /ʒ/)

  • Velar: Back of the tongue against soft palate (e.g., /k/, /g/)

Coarticulation

  • Definition: The overlap in articulation of sounds, where one sound starts before the previous one ends.

  • Enhances the fluency and efficiency of speech.

  • Types of Coarticulation

  • Anticipatory (Forward): Preparing for an upcoming sound while producing the current one (e.g., the lips prepare for 'sh' in 'shoe').

  • Backward Coarticulation: Influence of a preceding sound on a following sound (e.g., nasality in the vowel of 'mat' due to the nasal consonant).

Speech Features

  • Stop Gap and Burst

  • Stop Gap: Silence between consonants indicating obstruction.

  • Burst: Release of airflow after the constriction.

  • Aspiration

  • Follow the burst, brief duration (10-30 milliseconds).

  • Voiceless consonants typically have longer bursts and aspiration compared to voiced consonants.

  • Duration of Voiced vs. Voiceless Consonants

  • Voiced stop consonants (e.g., 'b') are about 10 milliseconds long.

  • Voiceless stop consonants (e.g., 'k') can be significantly longer (around 60 milliseconds).