Speech Sound Acquisition

Sounds developed at **age 2** include:

P B D M N H W

Sounds developed at **age 3** include:

K T G NG F Y

Sounds developed at **age 4** include:

V S Z SH CH J L

Sounds developed at **age 5** include:

TH (Voiced) ZH R

Sounds developed at **age 6** include:

TH (Voiceless)

Intelligibility at **age 1**:

25%

Intelligibility at **age 2**:

50%

Intelligibility at **age 3**:

75%

Intelligibility at **age 4**:

100%

Speech sound errors that ***disappear by age 3***:

Reduplication

Weak/Unstressed Syllable Deletion

Consonant Assimilation

Prevocalic Voicing

Fronting of Velars

Final Consonant Deletion

Diminutization (Addition of /i/ to word; “Doggy”)

Speech sound errors that ***persist after age 3***:

Final Consonant Devoicing

Consonant Cluster Reduction

Stopping (A fricative or affricate is replaced by a stop)

Epenthesis (A schwa vowel is inserted)

Gliding (A liquid is produced as a glide)

Depalatalization

Vocalization