Effects of variation in timing of palatal repair on articulation skills in complete cleft lip and palate cases--a retrospective study.

The effects of variation in the timing of palatal repair on articulation skills in complete cleft lip and palate was evaluated from fifty subjects. The present study confirmed that development of articulation was similar in the groups operated upon before 24 months and between 24 to 36 months. The insignificant difference suggests that articulation was good irrespective of the early or medium timing of palatal repair.

Auditory functions in anaesthesia residents during exposure to operating room noise.

Twenty anaesthesia residents were exposed to a pre-recorded audio cassette of operating room noise. The noise level during exposure was maintained at 77.32 +/- 1 dB (A), which was the calculated average operating room noise in our institute. Two auditory functions i.e., speech reception threshold and speech discrimination were studied before and during exposure to noise in a pre-fixed order. The right and left ears were tested separately. Speech reception threshold showed a mean increase of 23.75 +/- 6.86 dB (A) for the right ear and 26.25 +/- 6.90 dB(A) for the left ear during exposure to noise, suggesting that speech communication may be possible only by raising the voice. Speech discrimination showed a mean percentage decrease of 23.3 +/- 4.82 per cent for the right ear and 23.5 +/- 3.89 per cent for the left ear implying that there can be a steep decrease in the ability to discriminate spoken words.

Brain stem electric response audiometry in neonates with hyperbilirubinemia.

Auditory evoked responses using BERA were studied in 30 newborn babies with plasma bilirubin > or = 15 mgm/dl and repeated after treatment of neonatal jaundice with bilirubin levels of < or = 10 mgm/dl. A few jaundiced babies (16.5%) showed absent BERA response at the initial/subsequent examination. After treatment, 3/30 babies showed absent wave form responses and 2 of these were clinically kernicteric. Jaundiced babies had prolonged wave peak latencies and inter peak latencies. Treated babies showed a tendency towards recovery in their BERA responses which were however not complete. Total plasma bilirubin value at the time of BERA examination and mean maximal bilirubin values had no correlation with the incidence and degree of BERA abnormalities.

Electrical response audiometry (ERA) in infants.

The electric response audiometry is a useful diagnostic technique for identifying hearing loss in infants. Among the various electrical responses, the BSER enables us to arrive at an accurate early clinical diagnosis of hearing loss in infants so that effective auditory input, which is the prime requisite for the conceptual foundation for the growth of communication, can be provided through appropriate intervention programmes. The electric response audiometry provides information regarding the physiologic state of the peripheral organs and auditory pathways but however, cannot ascertain whether the infant can hear, in terms of perceiving auditory information. Inspite of this major limitation, the growing acceptance of brainstem electrical potentials in clinics and laboratories throughout the world attests to their increasing importance especially in the assessment of hearing sensitivity of infants.

Brain stem evoked response audiometry in neonates.

Brain stem evoked response audiometry (BERA) was performed in 50 normal full term newborn infants (25 male, 25 female) to generate normative data base for this age group. The stimuli of 30 dB, 40 dB and 80 dB nHL (normal hearing level) intensities were delivered to each subjects. 30 dB stimulus failed to produce clear wave patterns, whereas upto six vertex positive waves were recognised among which waves I, III and V were commonly present. The absolute latencies of waves I and V at 40 dB nJL were 2.54 +/- 0.21 msec and 7.56 +/- 0.26 msec and at 80 dB nHL these were 2.06 +/- 0.15 msec and 7.09 +/- 0.17 msec respectively. I-V interpeak latencies (IPL) were 5.02 +/- 0.13 msec at 40 dB and 5.03 +/- 0.13 at 80 dB nHL. The latencies of waves I and V were decreased with the increase of intensity of stimuli with the rate of 0.012 msec/dB, bit I-V IPL, i.e., central conduction time remained almost constant. There were no statistically significant differences in the brain stem auditory evoked responses between male and female subjects. Brain stem evoked response audiometry is objective and reliable for hearing screening in neonates.