PURPOSE: to improve knowledge on the effects of reverse phonation technique based on an analysis of its efficiency on normal female voice, using wideband and narrowband spectrograph. METHODS: 32 young adult women who signed the Informed Consent were submitted to otorhinolaryngologic evaluation and speech and hearing screening in order to avoid alterations that could interfere in the results of the study; voice samples were collected before and after three series containing 15 reverse phonation repetitions, at maximum phonation time with habitual tone and intensity, and 30-seconds interval of passive rest between the series. We used the Real Time Spectrogram software (Kay Elemetrics Corp.) to generate wideband and narrowband spectrograph. Data were analyzed by means of the simple percentage and the Qui-Square test, with a significance level of 5%. RESULTS: there was a trend to increase in the definition of harmonics; an increase in the regularity the spectrograph; in the intensity and definition of Formants 3 and 4 frequencies; in the intensity of high frequencies and in the entire spectrum; as well as a significant increase in the definition of Formant 1. CONCLUSION: finally, we believe that the technique enables the stretching and vibration of the vocal folds, with a possible homogenization and modifications in the mucous, consequently improving the vocal signal with a higher vibration regularity and an improvement in resonance.