Digits might share “phonemic similarity”

[dohboy]

Judging from the Posts, you have an expertise in phonemes and phonetics.

My doctoral dissertation is computerizing a new form of the classic psychological test call the “Digit Span” (DS) test and it is testing the validity of the new test. The examiner presents verbally and the examinee recalls orally back to the examiner sets of digits (zero through nine) in the same order, then backwards, and finally in ascending order.

Here is where my question comes in.
In the latest revision of the DS test, the publisher, Psychological Corp, has removed the digits “5” and “9” where they might occur in the same series of digits (“intratrial repetition”) presented to the examinee. The publisher cites “5” and “9” share a “phonemic similarity.” Quoting from the WAIS-IV technical manual (the DS test is a subtest of the WAIS-IV):

"... Eleven trials from the WAIS-III were retained in Digit Span Forward and 5 were retained in Digit Span Backward. Five trials for Digit Span Forward and nine trials for Digit Span Backward were modified to more evenly distribute the use of each of the nine digits and to minimize or eliminate intratrial repetition of digits with phonetic similarity (i .e., the number 9 and the number 5)." Wechsler, D. (2008). WAIS-IV technical and interpretive manual (p. 15). San Antonio, TX: Psychological Corporation.

For the new computerized DS test, I created an original digit series to respect the publisher’s copyright held for the unique digit series presented on the Wechsler DS test. Also, as did Psychological Corp., I want to eliminate potential confusion between digits that may be presented verbally and sound similar to the examinee:

In addition to “5” and “9”, what other digits might share “phonemic similarity” with one another? I was not able to get the attention of the publisher with my question; so, I thought I might ask you.

What are your thoughts?

[Percy Henry]

Greetings Jim,


Below, please find the phonetic representation of the digits (0-9). The first is the IPA representation (see http://dictionary.reference.com); the second in braces is the US English or AT&T SAPI 5 Phoneme Set representation.


0. ˈzɪəroʊ {z iy r 1 ow}

1. wʌn {w ah n}

2. tu {t uw}

3. θri {th r iy}

4. fɔr, foʊr {f ao r, f ow r}

5. faɪv {f ay v}

6. sɪks {s ih k s}

7. ˈsɛvən {s eh v 1 ax n}

8. eɪt {ey t}

9. naɪn {n ay n}


As you can see "5" and "9" share the phoneme "ay" as the second phoneme and are three phoneme in length. That is the only obvious similarity.

[dohboy]

Thank you.