Effects of varying the intensity of the primary tones on the amplitudes of Distortion Product Otoacoustic Emissions (OAEdp) in patients with normal hearing

Indexación: Web of Science; ScieloIntroducción: Las emisiones otoacústicas (EOA) son sonidos generados por las células ciliadas externas (CCE). Se ha visto que la generación y registro de las EOA evocadas depende de factores técnicos de evaluación como el nivel de intensidad de los tonos primarios, relación frecuencial entre los tonos, etc. Objetivos: Estudiar el efecto de la variación de la intensidad de los tonos primarios en la amplitud de la respuesta de las EOA producto de distorsión (pd) en individuos con audición normal. Material y método: Se evaluaron 35 individuos a los cuales se les midieron EOApd utilizando diferentes intensidades de tonos primarios: Intensidad baja (I1=50dBSPL e I2=50dBSPL), intensidad media (I1=55dBSPL e I2=65dBSPL) e intensidad alta (I1=70dBSPL e I2=70dBSPL). Resultados: Se observó que para tonos primarios a bajas intensidades (I1=50dBSPL e I2=50dBSPL) existe una disminución tanto en amplitud y presencia de las EOApd, mientras que para tonos primarios a intensidades mayores (I1=55dBSPL e I2=65dBSPL - I1=70dBSPL e I2=70dBSPL) se evidenció un aumento en amplitud y presencia de EOApd en los sujetos estudiados. Conclusión: Se evidencian diferencias estadísticamente significativas en la amplitud de las EOApd al variar la intensidad de los tonos primarios. Por lo cual se puede establecer que las intensidades medias-altas son las más adecuadas para la evaluación de EOApd en sujetos con audición normal.Introduction: Otoacoustic emissions (OAE) are sounds produced by outer hair cells. The generation and recording of evoked OAE depends on technical factors such as level of intensity of primary tones, frequency relationship between the tones, etc. Aim: To study the effect of varying the intensity of primary tones in the amplitude of the response of Distortion Product OAE (DP) in individuals with normal hearing. Material and method: 35 individuals were measured using different intensities OAEdp primary tones: Low Intensity (I1= I2 =50dBSPL 50dBSPL e), Medium Intensity (11= I2 =65dBSPL 55dBSPL e) and High Intensity (I1 =70dBSPL and I2 =70dBSPL). Results: Using Low primary tones (I1 =I2 =50dBSPL 50dBSPL) there is a decrease in amplitude and presence of DPOAE, while for primary tones at higher intensities (I1 and I2 = = 55dBSPL 65dBSPL -11 =70dBSPL and I2 =70dBSPL) an increase in amplitude and presence of OAEdp in subjects with normal hearing was observed . Conclusion: There are statistically significant differences in OAEdp amplitude by varying the intensity of the primary tones. Therefore medium-high intensities are best suited for the evaluation of OAEdp in subjects with normal hearing.http://ref.scielo.org/36dbs

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions