3 groups, the normal hearing children(NH) and the congenital profound hearing-impaired children who received the cochlear implant(CI) or wore the hearing aid(HA) in their 3-5 years old, are compared acoustically in each Korean seven monophthongs. The H1-H2(first two harmonic differences) and the spectral tilt were chosen as acoustic parameters. The results showed that the difference in H1-H2 among three groups was statistically significant. In the males, /?/ was NH<HA HA>CI, /a/ and /?/ was NH>HA, HA<CI. In the female, /i/ was NH<HA, /?/ and /o/ was NH>CI, HA>CI, and finally /a/ was NH>CI, HA<CI. Another result revealed that the difference of spectral tilt among groups was statistically significant. In the male, /?/ was NH<CI, HA<CI, /a/ and /?/ was NH<HA, HA>CI. In the female, /i/ was NH>HA, /?/ and /o/ was NH<CI, HA<CI, and finally /a/ was NH<HA, HA>CI.