ABSTRACT
Without visual information, blind speakers rely solely on the auditory signal to recover phonological information. We wanted to measure the psychoacoustic measures and perception of compressed speech in noise in individuals with congenital and acquired blindness and correlate the temporal resolution and frequency resolution ability with individuals with normal sight.METHODSThe clinical group (age range-12-20 years) contains two subgroups- congenital blindness and acquired blindness, with normal hearing each containing 15 participants. 15 participants with normal vision were selected as controls. To measure the temporal processing ability each participant was asked to perform Gap detection test. Similarly, difference limen frequency was estimated from pitch discrimination of pure tones. The task for speech perception of compressed sentences was done at different rate of compression at different SNRs.RESULTSResults indicated that there was significant difference in gap detection threshold between congenital blinds and normal sighted participants as well as between acquired blinds and normal sighted participants. There was significant difference in frequency discrimination scores between blind listeners and normal sighted participants. The sentence perception score was better in those participants who have congenital blindness than acquired blindness followed by normal sighted participants in each experimental condition.CONCLUSIONSFrom the investigation, it can be concluded that the psychoacoustic measures are better in individuals with blindness than individuals with normal sight. speech perception deteriorates with an increase in noise in both normal sighted individuals and individuals with blindness. Effect of noise is more for individuals with normal sight than blind listeners.
ABSTRACT
Introducción. Los prematuros con edad de gestación (EG) igual o menor de 32 semanas y peso al nacimiento (PN) menor de 1 500 g, tienen un alto riesgo de ceguera irreversible por retinopatía de la prematurez (ROP). Países industrializados han desarrollado sus propias guías de tamizaje ocular basadas en la EG y PN. Cuan-do estos criterios se han aplicado en países en vías de desarrollo, han subestimado pacientes con riesgo de ROP. El objetivo de este trabajo es determinar los parámetros de EG y PN asociados al desarrollo de ROP en un hospital de tercer nivel de la Ciudad de México. Métodos. Las retinas de 82 pacientes fueron examinadas y divididas en dos grupos: ROP presente (n =26) y ROP ausente (n=56). Resultados. Los prematuros con EG menor de 30 semanas (razón de momios [RM] =5.67, intervalo de confianza de 95% [IC95%] =1.63-19.76) y PN igual o menor de 1 250 g (RM= 8.15, IC95% =2.08-31.88) tienen mayor riesgo de desarrollar ROP, comparado con pacientes de EG de 33 a 36 semanas y PN de 1 500 a 2 000 g, respectivamente (P <0.01). Conclusiones. Los prematuros con EG menor de 30 semanas y PN igual o menor de 1 250 g, tienen alto riesgo de presentar ROP y desprendimiento de retina. Se requiere de un acuerdo nacional que nos permita establecer los parámetros de EG y PN para el tamizaje ocular en prematuros mexicanos.
Introduction. Newborns with gestational age (GA) ≤ 32 weeks and birth weight (BW) < 1 500 g are at risk of irreversible blindness secondary to retinopathy of prematurity (ROP). Developed countries have established their own eye screening guidelines based on GA and BW. However, when these criteria have been applied in developing countries, patients at risk have been underestimated. Our objective is to determine GA and BW parameters associated to the development of ROP in a México City tertiary care hospital. Methods. Retinas of 82 newborns were examined and divided in 2 groups: with ROP (n =26) and without ROP (n =56). Results. Newborns with GA < 30 weeks (OR =5.67, 95% CI = 1.63-19.76) and BW ≤ 1 250 g (OR =8.15, 95% CI =2.08-31.88) had higher risk of developing ROP compared with patients having GA 33 to 36 weeks and BW 1 500 to 2 000 g, respectively (P<0.01). Conclusions. Newborns with GA < 30 weeks and BW < 1 250 g are at higher risk of developing ROP and thus retinal detachment. A national agreement on ROP screening that allows us to determine GA and BW parameters for eye examination in Mexican newborns is needed.