Phonological Development/ Phonological Processes

Infant production:

Early babbling: relies 1. on auditory info, 2. reflects perceptual saliency, 3. reflects maturation, 4. relfects ease of production
reduplicated babbling: repition of identical CVCV shape (mama)
variegated babbling: Changing consonant/ vowels in babbled stream (bada)
Infants produce single syllable words first (V, CV shapes first)
Stops & nasal emerge first
corner vowels often emerge first
frequent use of central vowels

Trends in development:

Larger inventory of sounds found in the initial position
Voiced stops preceded voiceless
Great degree of variability for /r/ & /s/
+ /s/ = “stopped” with /t,d/ substitution when children are younger/ produced as dentalized or laterlized when kids lose teeth
+ /r/ differs across countries & w/in dialects of US

Impact of babbling on later language:

children who babble= more vowels/ consonants show less lang growth
children who bbable w/ great complexity show more language growth
children who babble diverse consonant productions show more lang growth
5-10 mos children show canonical babbling = on track for critical development (ba ba ba, ma ma ma, da da da)
onset of canonical babbling= somewhat consistent across langs

Transition from babble to speech:

- Comprehension precedes production

- Production of gestures= speech

- Intentionality= moving from vocal play to imitation of adults

Phonological reorganization:

- Sound production varies from word to word

- Words shpes similar to adult model

- Early word form may be similar

First 50 words:

Variability in children early.. BUT
Evidences finds that standard deviation (range of when children learn) decilines between 18- 24 mos which is when we identify late talkers
Late talkers = children who by 24 mos

- Havent reached 50 words

- Not combining words into phrases

Phonological Processes:

Systematic and common categories include:
- Substitution processes: These involve one phoneme being replaced by another in speech. Substitution processes are indicative of underlying phonological development issues and can manifest in various ways, which aids in understanding speech disorders.
- Assimilation processes: Characterized by changes to sounds based on neighboring sounds, leading to alterations that reflect the influence of adjacent phonemes. This process highlights the fluidity and interconnected nature of speech sounds.
- Syllable structure processes: These affect the structure of the syllables in speech, illustrating how children simplify complex syllable forms for easier articulation. These processes are crucial for assessing typical speech development.

Multiple phonological processes can occur simultaneously, making it challenging to pinpoint specific areas of difficulty in a child's speech. Each process may contribute to a child's overall intelligibility and clarity of speech.
Processes are linked to phonological/phonemic development, particularly with late-developing sounds, which can guide clinicians in their assessment and intervention strategies.
Voicing distinctions are usually preserved in errors, except for specific cases where children exhibit systematic errors, impacting communication and comprehension.

Common substitutions:
- Velar/palatals (/k/, /g/, /ʃ/) --> alveolars (/t/, /d/, /s/): This is known as Backing, where sounds produced further back in the mouth are replaced with sounds produced more forward.
- Alveolars (/t/, /d/) --> velars (/k/, /g/): Known as Fronting, this process occurs when a child substitutes a sound produced at the alveolar ridge with a sound produced further back in the mouth.
- Various other substitutions (gliding, stopping, vowelization, etc.) can occur, revealing the complexity of phonological development. These substitutions can significantly affect speech intelligibility and are crucial for interventions by speech-language pathologists (SLPs).

Key types include:
- Changes in consonants to similar sounding ones reflect Assimilation, where sounds become more alike due to their phonetic context, enhancing the fluidity of speech. (“bub” for “bus”)
- Nasals changing to non-nasals (Denasalization) showcases how the phonetic characteristics of one sound can alter another. (Doze for nose)
- Voiced consonants at word ends becoming voiceless (Final Consonant Devoicing) can indicate developmental progress or areas needing attention, especially in young children. (pick for pig)
- Voiceless consonants at word beginnings becoming voiced (Prevocalic Voicing) is another common phenomenon that presents challenges in understanding children's speech patterns. These processes can be perceived differently depending on the listener's familiarity with child speech. (gomb for comb)
- Reduplication: Complete

Types include:
- Reduction of consonant clusters (Cluster Reduction) simplifies complex consonant combinations, which is a common aspect of early speech development. (pane for plane)
- Omission of final consonants (Final Consonant Deletion) significantly impacts speech intelligibility, leading to potential misunderstandings. (toe for toad)
- Omission of initial consonants (Initial Consonant Deletion) may further obscure clarity, necessitating targeted therapies from SLPs. (unny for bunny)
- Deletion of weak syllables (Weak Syllable Deletion) often highlights a child's effort to simplify speech at a young age. (nana for banana)
- Addition of sounds between consonants (Epenthesis) reflects children's attempts to articulate complex sounds better and impacts their overall speech production. (bu-lue for blue)

Normative data indicates:
- Nasal, stop, and glide sounds are typically acquired early, showcasing the natural progression of sound development among children.
- Fricatives and affricates are acquired later, indicating more complex articulatory skills that require maturation of the vocal tract.
- Most phonological processes resolve by age 3, with some exceptions that can inform clinical assessments. Delays in resolution may signal a need for speech intervention services.

Understanding phonological processes is vital for speech therapists in assessing and intervening in children's speech sound development. Effective identification of these processes can enhance intervention strategies, leading to improved communication outcomes for children with speech sound disorders.