• Norms for Speech Development (Articulation, Phonology, & Intelligibility) Utilized by EES

     

     
    Iowa-Nebraska Norms for Phonetic Acquisition

    *These ages represent the 90% level of phonetic acquisition for in single words for boys and for girls, according to the Iowa-Nebraska Articulation Norms Project (JSHD, Nov. 1990, Smit et al). These are the guidelines adopted in the “current” Indiana State Guidelines (1994). If a child is not making a sound by the designated age, they are below the expected age level for that sound; however, additional factors such as negative educational impact, stimulability, and consistency of error must also be considered prior to determining eligibility for Special Education Services based on these errors.

     

    *These are recommended ages for phonetic acquisition only. If a student’s error on phoneme or cluster is a phonological process affecting other similar sounds, that process should be treated at an age appropriate for that process (see Expected Ages for Phonological Process Suppression chart). See Speech Sound Development Chart for a chart which combines both phonetic acquisition and phonological processes.

     

    *The information below this chart describes variables to consider for /s,z/ phonemes.

     

    *All vowels should be produced correctly by age 3.

     

     

    Phoneme

    90% Acquisition for Females by age in years and months

    90% Acquisition for Males

    by age in years and months

    /m/

    3.0

    3.0

    /n/

    3.6

    3.0

    /ng/

    7.0-9.0

    7.0-9.0

    /h/

    3.0

    3.0

    /w/

    3.0

    3.0

    “y”

    4.0

    5.0

    /p/

    3.0

    3.0

    /b/

    3.0

    3.0

    /t/

    4.0

    3.6

    /d/

    3.0

    3.6

    /k/

    3.6

    3.6

    /g/

    3.6

    4.0

    /f/

    3.6 Initial position

    5.6 Final position

    3.6 Initial position

    5.6 Final position

    /v/

    5.6

    5.6

    “th” unvoiced

    6.0

    8.0

    “th” voiced

    4.6

    7.0

    /s/

    7.0-9.0 (see guidelines below)

    7.0-9.0 (see guidelines below)

    /z/

    7.0-9.0 (see guidelines below)

    7.0-9.0 (see guidelines below)

    “sh”

    6.0

    7.0

    “ch”

    6.0

    7.0

    “J”

    6.0

    7.0

    /l/

    5.0 Initial position

    6.0 Final position

    6.0 Initial position

    7.0 Final position

    /r/

    8.0

    8.0

     

    Variables to Consider for /s/ and /z/:

    This section has been lifted directly from the current Indiana guidelines (1994):

     

    “The following variables should be taken into consideration when using predictive assessment of phonetic errors on /s/ and /z/:

     

    1. Consistency of the Error: Smit et al also recommend that “a child exhibiting inconsistency (i.e. if the /s,z/ could be produced correctly in any context) would not usually be considered for intervention unless the so-called inconsistency was governed by a phonological rule or was powerfully conditioned by phonetic context.”

    2. Dentition: Dental conditions, such as the lack of eruption of the upper incisors, are important diagnostic considerations for the /s,z/ phonemes.”

     

    Smit et al, in their findings from the Iowa-Nebraska Norms project (JSHD, Nov. 1990) make the following recommendations regarding eligibility for therapy for /s,z/ errors. Items in [ ] have been added or changed for the purposes of school-based intervention.

     

    1. “Consider intervention for lateralized variants, other rare variants and variants that appear to have damaging social consequences at or before age 7.0. In these cases early intervention is indicated, even for preschoolers, provided that

      1. The child appears to respond favorably to treatment (a decision that might be based on the outcome of a brief period of diagnostic remediation); and

      2. There are no indicators of spontaneous or impending improvement.

    2. For any other kinds of phonetic errors [not lateralized, rare, or socially damaging], [screen for evaluation] at age 7.0, but delay intervention if the deviation is considered slight or if any one of the following positive indicators is present:

      1. Acceptable /s,z/ is used in any single or clustered context, even if the acceptable sound is used in only one or a few words;

      2. The child is stimulable for acceptable /s,z/; or

      3. The permanent upper incisors have not erupted.

    3. Recheck the child at 8.0. Provide intervention only if there has been no change in indicators or if there has been a negative change.

    4. Recheck at age 9.0 and provide intervention for children who still have clinically significant errors on /s,z/.

    5. Use the same kinds of criteria for each word-initial cluster with /s/ IF the primary error on the cluster involves the /s/. [this is NOT referring to the phonological processes of cluster reduction or stopping]. If the primary error on the cluster involves another element, for example /r/ as in /spr str skr/, then use age 9.0 as the age of acquisition.

     

     

     

     

     

    Expected Ages for Phonological Process Suppression

     

    The “current” Indiana guidelines simply review all available research in this area rather than giving clear ages at which suppression of phonological processes can be expected. The research is very discrepant, so the comprehensive review is not particularly functional.

     

    Caroline Bowen is a respected member of the SLP community, and the ASHA website link for Phonological Disorders send readers directly to her chart. The references are fairly current at 1997-1998. This chart has been adapted from her information. We are adopting this chart for our local guidelines for phonological process development. To use this chart, a phonological process should be affecting a set of sounds. If a single sound is affected, use the phonetic acquisition chart.

     

    Note: There are some Phonological Processes we would be unlikely to enroll for in isolation. For example, we would not typically enroll a child to work ONLY on pre-vocalic voicing, word-final devoicing, weak syllable deletion, or consonant harmony. Additional factors such as stimulability, consistency of errors, and effect on intelligibility should still be taken into consideration when determining whether a child with a phonologic disorder is eligible for services.

    Phonological Process

    Example

    Suppressed (Gone) by Approximately

    (ages in years and months)

    Backing

    “cable” for “table”

    “goor” for “door”

    Non-developmental

    (Appropriate for intervention

    at any age)

    Initial consonant deletion

    “an” for “pan”

    “op” for “cop”

    Non-developmental

    (Appropriate for intervention

    at any age)

    Glottal replacement

    Uses a glottal stop (vocal cords making a hard “uh” sound) in place of sounds

    Non-developmental

    (Appropriate for intervention

    at any age)

    Pre-vocalic voicing

    “big” for “pig”

    3.0

    Word-final de-voicing

    “pick” for “pig”

    3.0

    Final consonant deletion

    “ba” for “back”

    3.3

    Fronting

    “tar” for “car”

    “bid” for “big”

    3.6

     

    Consonant harmony

    “mime” for “mine”

    3.9

    Weak syllable deletion

    “efant” for “elephant”

    4.0

    Cluster reduction

    “poon” for “spoon”

    “keen” for “clean”

    Most S-blends by age 5.0

    Most L-blends by age 5.5

    Most R-blends by age 5.5

    3-sound clusters by age 6.0

    (See cluster reduction chart below)

    Gliding of liquids

    “yeg” for “leg”

    “yun” for “one”

    5.0

    Stopping /f/

    “punny” for “funny”

    3.0

    Stopping /s/

    “tun” for “sun”

    3.0

    Stopping /z/

    “doo” for “zoo”

    3.6

    Stopping “sh,” “J,” and “ch”

    “tee” for “she”

    “dump for “jump”

    “tare” for “chair”

    4.6

     

    Stopping voiceless “th”

    “ting” for “thing”

    5.0

    Expected Ages for Phonological Process Suppression Continued: Suppression of Cluster Reduction

     

    Ages for development of clusters in published charts are often discrepant and misleading. This is primarily due to mis-interpretation of the Iowa-Nebraska age reports for clusters. True cluster reduction (i.e. reducing a two-sound cluster to a single sound) is suppressed at different ages for different clusters.

     

    Note: If an error on a cluster is due to a sound substitution, please refer to the phonetic development chart. For example, if a child says “pway” for “play,” this is a /w/ for /l/ phonetic error, not a cluster error.

     

    Reduction of a single cluster listed would not warrant eligibility. A pattern of multiple cluster reductions occurring at ages later than expected suppression would be required to consider eligibility. Additional factors such as stimulability, consistency of errors, and effect on intelligibility should still be taken into consideration when determining whether a child with a phonologic disorder is eligible for services.

     

    Cluster

    Examples

    Age at which less than 5% of children are reducing this cluster to a single sound

    (or to two sounds

    for a 3-sound cluster)

    (reported in years and months)

    SL

    “side” for “slide”

    “wide” for “slide”

    3.0

    SW, SKW

    TW, KW

    PL, GL

    PR, TR, DR, KR, GR

     

    “sing” for “swing”

    “wing” for “swing”

    “wy” for “try”

    “ty” for “try”

    “town” for “crown”

    “wown” for “crown”

    3.5

    SK

    FL

    “tunk” for “skunk”

    “sunk” for “skunk”

    4.5

    SM, SN, ST

    “mile” for “smile”

    “sile” for “smile”

    5.0

    SP, STR

    BL, KL, FL

    FR

    “sting” for “string”

    “wing” for “string”

    “ting” for “string”

    5.5

    SPL, SPR, SKR

    “sping” for “spring”

    “ring” for “spring”

    “ping” for “spring”

    6.0

    Adapted from Smit, A.B. (1993). Phonologic Error Distributions in the Iowa-Nebraska Articulation Norms Project: Word-Initial Consonant Clusters. J Speech Hear Res, 36, 931-947.

     

    Simplified “Rules” for Parents and Teachers

    For the purposes of sound development charts, the following “rules” help to appropriately reduce and simplify the information in the above chart.

     

    “Two sounds in most s-blends” by age 5

    “Two sounds in most l-blends” by age 5 ½

    “Two sounds in most r-blends” by age 5 ½

    “Three sounds in 3-consonant clusters” by age 6

     

    Speech Sound Development Chart

    (A Combined Chart for Single Phonetic Errors and Phonologic Suppression Patterns)

    A note to parents, educators, and physicians: Factors of stimulability, consistency, and number of errors must be considered when determining eligibility for school-based speech therapy. Negative educational impact must also be present. Please consult with a Speech-Language Pathologist if you have concerns about a child’s communication skills at any age. School services start at age 3.

    Age of child

     

    Error patterns which are atypical for each age and gender

    (child should not be making errors listed at their age or at younger ages)

    (90% phonetic acquisition or typical age of phonologic suppression)

    Errors which are NOT typical

    at ANY age

    Girls

    Lateral lisp (air out sides of teeth on /s,z/)

    Using /k, g/ for many sounds (“goo” for “do”)

    Leaving off beginning sounds (“all” for “ball”)

    Glottal replacement (throat sounds)

    Boys

    Lateral lisp (air out sides of teeth on /s,z/)

    Using /k, g/ for many sounds (“goo” for “do”)

    Leaving off beginning sounds (“all” for “ball”)

    Glottal replacement (throat sounds)

    3 years

     

     

     

    Girls

    Errors on /m/, /p/, /b/, /h/, /w/, /d/ or /n/

    Dropping ending sounds (by 3:3, “ba” for “bag”)

    Errors on /s/ (“tun” for “sun” - frontal lisp with tongue between teeth is OK at this age)

    Boys

    Errors on /m/, /p/, /b/, /h/ or /w/

    Dropping ending sounds (by 3:3, “ba” for “bag”)

    Errors on /s/ (“tun” for “sun” - frontal lisp with tongue between teeth is OK at this age)

    3 years, 6 months

    Girls

    Errors on /k/ (“tow” for “cow”)

    Errors on /f/-start of word only (“pun” for “fun”)

    Errors on /g/ (“do” for “go”)

    Errors on /z/ (“doo” for “zoo” - frontal lisp with tongue between teeth is OK at this age)

    Boys

    Errors on /k/ (“tow” for “cow”)

    Errors on /f/-start of word only (“pun” for “fun”)

    Errors on /n/, /t/, or /d/

    Errors on /z/ (“doo” for “zoo” - frontal lisp with tongue between teeth is OK at this age)

    4 years

    Girls

    Errors on /t/

    Boys

    Errors on /g/ (“do” for “go”)

    4 years, 6 months

    Girls

    Errors with “th” voiced (“broder” for “brother”)

    Boys

    5 years

    Girls

    Errors on /l/ (“wike” for “like”)

    Most /s/ blends should have two sounds (“mile” for “smile,” “tar” for “star”)

    Boys

    Most /s/ blends should have two sounds (“mile” for “smile,” “tar” for “star”)

    5 years, 6 months

    Girls

    Errors on /f/-end of word only (“sas” for “safe”)

    Errors on /v/ (“ban” for “van”)

    Most /l/ and /r/ blends should have two sounds

    Boys

    Errors on /f/-end of word only (“sas” for “safe”)

    Errors on /v/ (“ban” for “van”)

    Most /l/ and /r/ blends should have two sounds

    6 years

    Girls

    Errors on “th” unvoiced (“fink” for “think”)

    Errors on “sh” (“soos” for “shoes”)

    Errors on “ch” (“ticken” for “chicken”)

    Errors on “J” (“delly” for “jelly”)

    Boys

    Errors on /l/ (“wike” for “like”)

     

     

    7 years

    Girls

    Frontal lisp (tongue between teeth on /s/ and /z/, “thee” for “see”), unless student can imitate a model correctly (stimulable)

    Boys

    Errors with “th” voiced (“broder” for “brother”) Errors on “sh” (“soos” for “shoes”)

    Errors on “ch” (“ticken” for “chicken”)

    Errors on “J” (“delly” for “jelly”)

    Frontal lisp (tongue between teeth on /s/ and /z/, “thee” for “see”), unless student can imitate a model correctly (stimulable)

    8 years

    Girls

    Errors on /r/ (“wed” for “red”)

    Frontal lisp (“thee” for “see”), unless stimulable

    Boys

    Errors on “th” unvoiced (“fink” for “think”)

    Errors on /r/ (“wed” for “red”)

    Frontal lisp, (“thee” for “see”) unless stimulable

    9 years

    Girls

    Frontal lisp should be corrected

    Boys

    Frontal lisp should be corrected

    (Adapted by Karyn Todor, from Iowa-Nebraska Norms, Smit, 1990; and from C. Bowen, 1997-1998.)

    Intelligibility Chart

     

    Intelligibility. Some level of unintelligibility in connected speech is expected at younger ages.  Use this chart as a guide to examine intelligibility issues.

     

    Age of Child

    Expected Intelligibility

    by Parents

    (Lynch, Brookshire, and Fox (1980), p. 102, cited in Bowen (1998).

    Expected Intelligibility

    By Strangers

    (Dr. Peter Flipsen Jr., 2006;

    Pascoe, 2005)

    12 months

     

    25%

    18 months

    25%

     

    24 months

    50-75%

    50%

    36 months

    75-100%

    50-75%

    48 months

     

    100% (below 66% = good candidate for intervention)

     

     

    Certain speech errors have more impact on intelligibility than other speech errors.  For that reason, a first grader with only the  /k/ for /t/ and /d/ for /g/ error is more likely to be enrolled in therapy than a first grader with only the /b/ for /v/ and /s/ for “sh” error, even though they have the same number of errors.  We must look at the impact of student errors on classroom functioning, including intelligibility.