[Cry analysis of hypoacoustic children and normal hearing children]

We analyzed the spectrograms of the cry of deaf children and compared the results with those of normal children.

Twenty deaf children (0-2 years of age, both sexes) and 20 normal hearing children of both sexes within the same age range were studied. The deaf cases were selected from patients with high-risk pregnancies who are followed up at the National Institute of Perinatology (INPer), Department of Human Communication. Brainstem evoked potential responses were carried out in order to corroborate hearing loss in the affected group and to verify normal hearing in the other group. During physical examination in the Human Communication Clinic of the Inper, the cry was recorded with a Fisher tape recorder and MK2 unidirectional microphone. Sonograms were analyzed in the "Laboratorio de Bioacústica" of the Institute of the Human Communication (CNR) using the Software Cool Edit 96. We registered the fundamental frequency and 6 harmonic F1 at F6 (Hz). The cry frequencies of the deaf children were compared and of the normal hearing children using one-way analysis of variance. A typology of frequencies was organized by means of cluster analysis by the method of Ward and was compared with the study groups by means of contingency analysis (chi square).

No significant difference was demonstrated in the fundamental frequency or in the harmonic by means of the one-way analysis. With cluster analysis, 8 types were obtained that were not different when compared with the study groups. The hypothesis was rejected with the obtained data.

Upon confirmation of the obtained results, analysis of the spectrogram of deaf children at early ages does not have the ability to identify the problem and thus cannot be used as a method for early detection of deafness.