🆗Language and Cognition Unit 4 – Phonetics, Phonology & Speech Perception

Key Concepts and Terminology

• Phonetics studies the physical properties of speech sounds, including their production, transmission, and perception
• Phonology focuses on the organization and function of sounds within a particular language system
• Phones are the basic units of speech sounds, while phonemes are the smallest units that distinguish meaning in a language
• Allophones are variants of a phoneme that do not change the meaning of a word (aspirated vs. unaspirated /p/)
• Minimal pairs are two words that differ by only one phoneme, demonstrating the contrastive nature of phonemes (bat vs. pat)
• Suprasegmentals refer to aspects of speech that extend beyond individual segments, such as stress, tone, and intonation
• The International Phonetic Alphabet (IPA) is a standardized set of symbols used to represent speech sounds across languages

Sound Production and Articulation

• Speech sounds are produced by the coordinated actions of the respiratory, phonatory, and articulatory systems
• The respiratory system, including the lungs and diaphragm, provides the airstream necessary for speech production
• The phonatory system, consisting of the larynx and vocal folds, is responsible for voicing and pitch
• Articulators, such as the tongue, lips, and teeth, shape the airstream to create different speech sounds
• Consonants are classified by their place of articulation (bilabial, alveolar, velar), manner of articulation (stop, fricative, nasal), and voicing (voiced, voiceless)
• Vowels are described by their tongue height (high, mid, low), tongue advancement (front, central, back), and lip rounding (rounded, unrounded)
• Coarticulation refers to the influence of neighboring sounds on the production of a given speech sound, resulting in allophonic variations

Phonetic Transcription Systems

• Phonetic transcription is the visual representation of speech sounds using a set of standardized symbols
• The International Phonetic Alphabet (IPA) is the most widely used phonetic transcription system
  • IPA symbols are enclosed in square brackets [ ] to indicate phonetic transcription
  • Each symbol represents a distinct speech sound, regardless of the language
• Broad transcription captures the basic phonemic distinctions in a language, while narrow transcription includes more detailed phonetic information
• Diacritics are additional symbols used to modify IPA characters, indicating specific phonetic features (nasalization, aspiration, lengthening)
• Phonetic transcription is essential for documenting and comparing speech sounds across languages and dialects
• Transcription skills are crucial for language learning, speech therapy, and linguistic research

Phonological Processes and Rules

• Phonological processes are systematic changes that speech sounds undergo in different contexts within a language
• Assimilation is a process where a sound becomes more similar to a neighboring sound (place assimilation: "in-patient" → "im-patient")
• Dissimilation is a process where a sound becomes less similar to a neighboring sound to maintain contrast (Latin "arbor" → Spanish "árbol")
• Deletion is the removal of a sound in a specific context (final consonant deletion: "hand" → "han")
• Insertion is the addition of a sound in a specific context (epenthesis: "athlete" → "athalete")
• Metathesis is the reordering of sounds within a word ("ask" → "aks" in some dialects)
• Phonological rules describe these processes using formal notation, specifying the context and conditions under which they occur
• Understanding phonological processes helps explain sound variations and changes within and across languages

Speech Perception Mechanisms

• Speech perception involves the listener's ability to interpret and understand spoken language
• The auditory system, including the outer, middle, and inner ear, transduces acoustic signals into neural impulses
• The brain processes these neural impulses to extract linguistic information, such as phonemes, words, and sentences
• Categorical perception is the tendency to perceive speech sounds as distinct categories rather than a continuum
  • This allows listeners to maintain phonemic contrasts despite variations in pronunciation
• The motor theory of speech perception proposes that speech is perceived by referencing the listener's own articulatory gestures
• The dual-stream model suggests that speech perception involves both a ventral stream for mapping sounds to meaning and a dorsal stream for mapping sounds to articulatory representations
• Context, top-down processing, and linguistic experience also play crucial roles in speech perception

Acoustic Analysis of Speech

• Acoustic analysis examines the physical properties of speech sounds, such as frequency, intensity, and duration
• Spectrographic analysis provides a visual representation of speech sounds, displaying frequency, time, and intensity information
  • Formants, which are concentrations of acoustic energy at specific frequencies, are visible on spectrograms and help characterize vowels
• Fundamental frequency (F0) corresponds to the rate of vocal fold vibration and is perceived as pitch
• Harmonics are integer multiples of the fundamental frequency and contribute to the timbre of speech sounds
• Consonants are characterized by their noise components, such as the burst in stop consonants or the frication noise in fricatives
• Acoustic measurements, such as voice onset time (VOT) and formant transitions, provide objective data for studying speech production and perception
• Acoustic analysis is used in speech synthesis, speech recognition, and clinical assessment of speech disorders

Language-Specific Phonological Patterns

• Each language has its own inventory of phonemes and phonological rules that govern their use
• Phonotactic constraints specify the permissible sequences of sounds in a language (e.g., English allows /spl-/ onsets, but not /spm-/)
• Syllable structure varies across languages, with some allowing more complex onsets and codas than others
• Stress patterns and prosodic features, such as tone and intonation, are language-specific and contribute to the overall rhythm and melody of speech
• Language contact and historical changes can lead to the emergence of new phonological patterns or the loss of existing ones
• Infants are sensitive to the phonological patterns of their native language, which guides their speech perception and production development
• Understanding language-specific phonological patterns is essential for second language learning and teaching

Applications in Language Learning and Disorders

• Phonetic and phonological knowledge is crucial for effective language teaching and learning
  • Language learners must acquire the phonemic distinctions and phonological rules of the target language
  • Explicit instruction in pronunciation and phonological patterns can improve learners' speech production and comprehension
• Speech-language pathologists use phonetic and phonological principles to assess and treat speech and language disorders
  • Articulation disorders involve difficulties producing specific speech sounds or sound sequences
  • Phonological disorders are characterized by systematic simplifications or deviations from the typical phonological patterns of a language
• Acoustic analysis and spectrographic displays are used to visualize and quantify speech production in clinical settings
• Assistive technologies, such as text-to-speech and speech recognition systems, rely on phonetic and phonological models to generate and interpret speech
• Research in phonetics and phonology informs the development of evidence-based practices in language education and speech-language therapy