Introduction: Acoustic analysis of the voice with advance of the digital technology increases as a promising complementary exam for raising the diagnostic precision in laringology. Aim: Standardization of the acoustic measurement of fundamental frequency, Perturbations and noise in the normal voice of male and female brazilians. Study design: Clinical prospective. Material and method: Research was carried out from March to August of 1997 in the Otorlaryngological Clinic of the Clinical Hospital of the Faculty of Medicine of Ribeirão Preto of the University of São Paulo, using 80 volunteers of the city of Ribeirão Preto and its region, consisting of 40 males and 40 females, and selected by means of a triage. Digital recordings of the vowels /a/, /e/, and /i/ were utilized, originating in a sample of 240 acoustic signals, and submitted to the Program of Acoustic Voice Analysis, with the São Carlos School of Engineering of the University of São Paulo securing the acoustic measurements. Results: Mean values in relationship to sex and phonemes were obtained in the measurements of: Fundamental Frequency, Jitter (Directional Perturbation Factor, Perturbation Variation Index, Jitter Ratio, Jitter Factor, Period Perturbation Quotient), Shimmer (Directional Perturbation Factor, Amplitude Variation Index, Amplitude Perturbation Quotient), Spectral Noise Level, Harmonic-to-noise ratio, Harmonic-to-noise ratio cepstrum, Normalized Noise Energy e Breathiness ratio. Conclusion: The normalization of acoustic measurements is necessary to better know the normal voice. The great majority of obtained values are compatible with existing literature.
acoustic measures; normal voice; standardization
