| The production of normal voice and speech need power system, vibration system, resonance system, articulation organs, nervous system and hearing feedback system through a complex conduction and feedback interaction. However, the acoustic parameters of the voice in deaf children with hearing-impaired is few and the results are different. Although it has been recognized that the control of voice of frequency and amplitude in hearing loss children are abnormal, there is no research to evaluate these abnormalities objectively. With the cochlear implants and other hearing compensation equipments developing quickly, it is necessary to study the acoustic characteristics of voice in hearing-impaired children.Objective: The experiment is design to obtain the objective acoustic parameters of normal children by using the Multi-Dimensional Voice analysis Program(MDVP), to provide a theoretical basis for the clinical evaluation of the voice in children of different sex. To investigate the acoustic parameters of the vocal profile in profoundly deaf children by using the Multi-Dimensional Voice Program(MDVP), observe the differences of the acoustic parameters of voice samples between the profoundly deaf children and the normal children, quantify the frequency and amplitude control of voice in deaf children, establish an objective assessment model with multi-parameter for the voice of hearing impaired children, and provide an objective and effective voice reference for cochlear implantation.Methods:1 Subjects: all 71 subjects selected for attending this experiment were profoundly deaf children aged 6 to 12 who were studying in Shijiazhuang special education school, 34 were boys, 37 were girls. The average age was 8.9±1.9 years old. The controlled group contained 130 cases, aged from 6 to 12 years old. All of them were randomly selected from a primary school in Shijiazhuang of Hebei province.The selected objects had no history of voice disorders, breathing diseases, throat diseases and nervous system diseases. Appearance and motion of bilateral vocal cords were developed normally and had no evidence of organic laryngeal pathology on laryngoscope.2 The method of detection: observe the appearance of the vocal cords(vocal color and edge-smoothing), movement, glottal closure and features of mucosa by stroboscopic laryngoscope or electronic laryngoscope; detect the voice acoustic parameters: the voice acoustic parameters were measured mainly on a sustained vowel /ɑ:/ which were recorded by software named MDVP for three times. The voice samples were all recorded in an isolation booth. The ambient noise of the isolation booth was less than 45 d B. It was three times to the average values. The commonly used objective parameters is including fundamental frequency(F0), Jitter, Shimmer, v F0, v Am, Amplitude Perturbation Quotient(APQ) and Noise to Harmonic Ratio(NHR).Results: It showed that F0, Jitter, Shimmer, v F0, v Am, APQ, and NHR’s parameter values in normal children had no statistical difference(P>0.05). It is not yet considered that the objective acoustic parameters between different sexes are different in normal children. The result showed that compared with the normal children, parameter values of F0, Jitter, Shimmer, APQ and NHR in profoundly deaf children had no statistically difference(P>0.05), so it is not yet considered that parameter values of F0, Jitter, Shimmer, APQ and NHR in hearing loss children are different from normal children. In hearing loss children, Mean F0 was 268.61 Hz and consistent with the established normative data. Mean measurements of Jitter(0.95%), Shimmer(3.41%), APQ(2.25%) and NHR(0.12) were also within normal scope;However, parameter values of v F0 and v Am in deaf children had statistically difference(P<0.01). The notable feature of the acoustic analysis was a statistically significant elevation in v F0(2.61%)and v Am(23.57%).Conclusion:1 In normal children’s voice, there is no gender difference in objective multidimensional parameter values in childhood. Therefore, the objective acoustic assessment of voice in childhood can be made in no accordance with the gender.2 Parameter values of F0, Jitter, Shimmer, APQ and NHR in deaf children may be only associated with the appearance and function of vocal,while they have no significant association with hearing loss and the decline of hearing feedback system. The parameter values of F0, Jitter, Shimmer, APQ and NHR were not different between hearing loss children and normal children.3 Auditory deprivation results in poor long-term control of frequency(v F0) and amplitude(v Am) during sustained phonation. The inability to maintain a sustained phonation may represent the partial collapse of an internal model of voice and speech. |
PDF Full Text Request