The effects of an acquired profound hearing loss on speech production. A case study.

Three parallel studies conducted with an early adolescent male subject deafened by meningitis at age 11 are reported. Study 1 plotted phonetic errors in spontaneous and read speech, long-term average spectra and vowel formant frequencies. Study 2 measured the subject's speech intelligibility using monosyllabic word lists. Study 3 involved normal hearer 's ratings of the subject's speech 2 months and 30 months after the onset of deafness. The results obtained revealed a deterioration in both speech intelligibility and quality.