ABSTRACT
Survery and comparison between the physical characteristics of Distortion-Product Otoacoustic Emissions of 1- 59 day-old normal-hearing newborns refered to TUMS, Rehabilitation School , Audiology department , 2002. This analytical-descriptive study was conducted on the ears of 102 easy method selected newborns. The tests included: otoscopy , BOA, Immittance audiometry , DPOAEs, and ABR if necessary. The amplitude and frequency of 2f[1]-f[2] emissions of DPOAEs evoked by two pure tones [L1=65 dBSPL , L2=50 dBSPL and f2/f1=1.2] were also calculated. All normal hearing newborns have normal DPOAEs. No significant difference was observed in test-retest. The amplitude of the DPOAEs to the right ear is significantly greater than the amplitude of the left ear [P<00.05]. No significant difference was observed between newborn's DPOAEs in terms of their gender. DPOAEs could be measured quickly and noninvasively and are excellent tools for the screening of newborn hearing loss. The results are valid only within the Context of this research
ABSTRACT
To assess neonates and children suffering from meningitis , during the critical and recovery periods , using ABR , EOAE and Behavioral Audiometry. 40 neonates to 12-year-old children were assessed. Using ABR test, the hearing of these cases was evaluated during the critical period-that is , 24-72 hours following the diagnosis. This test was repeated when patients recovered from meningitis-that is 24 hours before discharge [recovery period] Hearing function , again , was assessed 7-14 days following discharge through Immittance Audiometry, Behavioral Audiometry [PTA , SF and BOA]. And EOAE [TEOAE and DPOAE] tests procedures. During the critical period , ABR test revealed normal hearing in 35 patients [87.5%] and severe to profound sensorineural hearing loss [unilateral and bilateral] in 5 patients [12.5%-girl=4, boy=1]. The same result were obtained in reevaluation in the recovery period. On the other hand , 7-14 days after of discharge , Immittance Audiometry and Behavioral Audiometry [including PTA , S.F and BOA tests], confirmed the mentioned results [cross - gcheck]. EOAE test [DPOAE and TEOAE] in 35 normal hearing patients [according to ABR test] , showed normal cochlear function. 2 out of 5 cases suffering from severe to profound sensorineural hearing loss revealed normal cochlear function. According to EOAE results , abnormal cochlear function was evident in 3 patients. ABR , EOAE tests , and Behavioral Audiometry in children meningitis during the critical period and recovery period can be used to diagnose any degree of hearing loss with a high level accuracy. The results of persent study is confirmed by previous investigations