Background:
Partial deafness (PD) is a condition in which normal hearing is preserved in the low frequency range, while severe to profound hearing loss is observed in the middle and high frequency ranges. The aim of this study was to assess the acoustic structure of the voice in children considered for partial deafness treatment (PDT).

Material and Methods:
The material included 127 children aged from 5 to 12 years old. The study group included children with partial deafness (PD). Depending on age, patients in the study group were divided into 2 groups. The first included 40 children aged 5–6 years, and the second consisted of 44 school-age children aged 7–12 years. The control group included 20 healthy normally hearing children aged 5–6 years and 23 healthy, normally hearing children with clear voices, aged 7–12 years. Children’s voices were assessed subjectively by the physician and objectively with the use of a digital CSL KAY Multidimensional Voice Profile analyser (MDVP). The sustained vowel “a” was used for analysis.

Results:
Acoustic features of PD vs. normally hearing children were different. Statistically significant parameters differentiating voices in the group of younger children were fundamental frequency (Fo); shimmer, a parameter describing changes in amplitude (ShdB); and noise-to-harmonic-ratio (NHR). In the group of older children more acoustic parameters characterizing voices of PD children were defined. They included fundamental frequency (Fo); fundamental frequency variation (vFo); amplitude change (vAm, sAPQ); noise-to-harmonic-ratio (NHR); and voice tremor (FTRI).

Conclusions:
The acoustic structure of the voice in children with partial deafness is different from that in children with normal hearing.