Table 1.
Descriptive statistics for the proportion of vowels correct across speech recordings from persons with Down syndrome (N = total number of speech recordings, generally several recordings per speaker).
| Speaker Group | Vowel type | N | Minimum | Maximum | Mean | SD |
|---|---|---|---|---|---|---|
| Overall | /i/ | 143 | 0.42 | 1.00 | 0.94 | 0.11 |
| /u/ | 143 | 0.17 | 1.00 | 0.93 | 0.15 | |
| /æ/ | 143 | 0.12 | 1.00 | 0.82 | 0.24 | |
| /ɑ/ | 143 | 0.09 | 1.00 | 0.73 | 0.25 | |
| Male | /i/ | 75 | 0.42 | 1.00 | 0.91 | 0.14 |
| /u/ | 75 | 0.17 | 1.00 | 0.90 | 0.19 | |
| /æ/ | 75 | 0.17 | 1.00 | 0.74 | 0.26 | |
| /ɑ/ | 75 | 0.09 | 1.00 | 0.69 | 0.26 | |
| Female | /i/ | 68 | 0.80 | 1.00 | 0.98 | 0.05 |
| /u/ | 68 | 0.60 | 1.00 | 0.97 | 0.07 | |
| /æ/ | 68 | 0.12 | 1.00 | 0.89 | 0.17 | |
| /ɑ/ | 68 | 0.24 | 1.00 | 0.78 | 0.23 |
Note. The table displays the statistics broken down by vowel type for all (top), male individuals only (center), and female individuals only (bottom). N = speaking occasions.