Table 4.
Average (SD) first formant (F1) and second formant (F2) frequencies in mels for the point vowels /i/, /ɑ/, and /u/ in infant-directed (ID) and adult-directed (AD) speech to participants with hearing impairment fitted with cochlear implants (HI-CI, Study 1) or hearing aids (HI-HA, Study 2), their chronological-age matches with normal hearing (NH-CAM), and their hearing-experience matches with normal hearing (NH-HEM).
| Hearing status | Speech style | /i/ |
/ɑ/ |
/u/ |
|||
|---|---|---|---|---|---|---|---|
| F1 | F2 | F1 | F2 | F1 | F2 | ||
| Study 1 | |||||||
| HI-CI | AD | 475 (28) | 1866 (60) | 835 (73) | 1238 (126) | 526 (40) | 1531 (104) |
| ID | 481 (36) | 1924 (51) | 842 (60) | 1300 (77) | 520 (50) | 1409 (146) | |
| NH-CAM | AD | 495 (21) | 1852 (43) | 808 (122) | 1145 (195) | 499 (30) | 1475 (116) |
| ID | 495 (25) | 1895 (46) | 825 (62) | 1211 (141) | 525 (30) | 1391 (150) | |
| NH-HEM | AD | 502 (34) | 1805 (76) | 869 (53) | 1232 (45) | 508 (25) | 1510 (92) |
| ID | 490 (33) | 1895 (36) | 839 (80) | 1291 (94) | 534 (54) | 1440 (163) | |
| Study 2 | |||||||
| HI-HA | AD | 515 (33) | 1853 (59) | 829 (64) | 1209 (80) | 522 (24) | 1523 (94) |
| ID | 524 (46) | 1933 (77) | 814 (54) | 1272 (97) | 527 (45) | 1469 (93) | |
| NH-CAM | AD | 485 (30) | 1842 (35) | 869 (28) | 1233 (61) | 498 (35) | 1526 (53) |
| ID | 500 (32) | 1892 (29) | 877 (51) | 1295 (56) | 524 (50) | 1456 (106) | |
| NH-HEM | AD | 484 (38) | 1853 (63) | 868 (46) | 1227 (36) | 505 (23) | 1488 (161) |
| ID | 485 (24) | 1914 (52) | 863 (81) | 1309 (66) | 516 (40) | 1398 (197) | |