[Harmonic/noise ratio and spectrographic analysis in vocal abuse pathology]. / La relación armónico/ruido y el análisis espectrográfico en la patología de abuso vocal.

Vocal abuse lesions disturb voice production by increasing the presence of noise in the voice. The harmonic-to-noise ratio (H/N) and spectrography are two different ways to evaluate noise components in the voice. A study was made of 52 patients (32 polyps, 11 Reinke's edema and 9 nodules) who underwent microlaryngeal phonosurgery. The grade of glottic closure was determined by stroboscopy; H/N and the long-term average spectrum (LTAS) at low-frequency (0-2000 Hz) were measured with a CSL-4300 instrument. Stroboscopy and acoustic analysis were made before surgery and two week and one month after surgery. Before surgery, the LTAS revealed weak harmonics, as shown by H/N values. After surgery, H/N values and harmonic energy increased. Preoperative and postoperative differences were significant (p < 0.05). Improved glottic closure after surgery improved the acoustic parameters.

[S/z ratio in glottic closure defects]. / El índice s/z en los defectos de cierre glótico.

The quotient between the maximum phonation time (MPT) of the sound /s/ and a vowel sound, measures the relation of resistances to the expiratory air flow. When the sound /s/ is emitted, resistance is located at the teeth, and when a vowel is phonated, the site of resistance is the glottis. Estimating the quotient instead of measuring only the MPT, we avoid the influence of respiratory alterations in the results. We evaluated the utility of the s/z ratio as a clinical indicator of laryngeal pathology in 72 patients with organic vocal cord pathology. We compared the results of the s/z ratio to the degree of glottic closure defect, measured by videolaryngostroboscopy. S/z ratio in 22 normal-speaking subjects was also measured. S/z ratio in normal-speaking subjects was nearly 1.0. When a glottic closure defect was present, the ratio was over 1.4. Organic lesions that difficult glottic closure, produce a decrease of air flow resistance and, therefore, a shortening of the MPT of the vowel sounds.

[Phonetograms in laryngeal lesions due to vocal abuse]. / Fonetograma en lesiones laríngeas por abuso vocal.

Using this test, we measure maximum and minimum vocal capacity (sound pressure in dB) from the lowest to the highest frequency that a person can emit and sustain. These measurements are represented on an easily interpreted graph that allows the magnitude of the vocal area to be evaluated. We made phonetograms of persons with nodules (3), polyps (16) and Reinke edema (10) and compared their results to those of a group of 25 healthy subjects. The vocal fields of patients with laryngeal polyp and Reinke's edema were severely reduced.

[Computerized study of perioperative difficulties of stapedectomy]. / Estudio computarizado de las dificultades perquirúrgicas de la estapedectomía.

A retrospective study of 1035 stapedectomies was performed to assess the incidence of intraoperative complications between 1972-1990. We found 45.89% of complications. We divided this alterations in 6 groups: 1) hemorrhage (20.67%), 2) stapes, foot plate, oval window (8.40%), 3) alterations in the middle ear (6.85%), 4) alterations in the incus (3.76%), 5) alterations in the external ear canal (3.57%) and 6) problems with protesis or graf (2.60%). We have analyzed these complications. We propose to carry out the solutions.