Assessment of impulse noise level and acoustic trauma in military personnel.

BACKGROUND: Military personnel are usually exposed to high levels of impulse noise (IN) which can lead to hearing loss. OBJECTIVES: The purpose of this study was to assess the effects of relatively low level exposure of impulse noise (IN) during shooting practice on hearing using pure tone audiometry (PTA) and transiently evoked otoacoustic emission (TEOAE) in military personnel. MATERIALS AND METHODS: Forty male soldiers (mean age 20.08 years) were recruited for the study. Prior to their first shooting practice, PTA and TEOAE were recorded. After 15 minutes and one week post- practice PTA and TEOAE were compared. RESULTS: Immediately after shooting practice significant differences in PTA at 500, 1000, and 4000 Hz were observed for the right ear and no significant difference at any frequency for the left ear. There was a significant difference in the amplitude of TEOAE 15 minutes after shooting practice at 500, 1000, 2000, 3000, and 4000 Hz in the right ear, while for the left ear the difference was significant at 1000 and 2000 Hz. One week after exposure a significant difference at 500 and 4000 Hz was found only in the right ear and a significant difference in the amplitude of TEOAE was observed at 500, 1000, 2000, 3000, and 4000 Hz. CONCLUSIONS: Even exposure lower than permissible levels may lead to acoustic trauma. TEOAE is more sensitive than PTA in detecting early hearing loss after military shooting exercises. Hearing protection equipment and appropriate surveillance programs are recommended.

Diagnostic efficacy of different methods in the assessment of adenoid hypertrophy.

OBJECTIVE: This study was designed for better understanding of the role of different methods of nasal endoscopy in the assessment of adenoid hypertrophy and comparing them with lateral neck radiography and patients' symptoms. SUBJECTS AND METHOD: From August 2007 until January 2009, in the otolaryngology ward of a tertiary referral center, 89 patients who had symptoms related to chronic mouth breathing participated in this study. History of the symptoms related to adenoid hypertrophy was obtained from them. In addition, all patients underwent nasal endoscopy and lateral nasopharynx x-ray. The clinician who did nasal endoscopy was blinded to information about clinical data and x-ray and vice versa. Afterward, the relationship between symptoms and each diagnostic procedure was evaluated. RESULTS: Patients had a mean age of 9.47 ± 4.68 years. In the evaluation of the relationship between symptoms grading and grading in lateral neck radiography, this relationship was significant about snoring. Furthermore, there was a significant relationship between the endoscopic size of adenoid and number of the episodes of acute otitis media. The sum of symptoms grading had a significant relationship with the size of adenoid in lateral neck x-ray, but not in nasal endoscopy. CONCLUSION: The results of the present study indicated that both radiography and nasal endoscopy could define the relationship between adenoid hypertrophy and associated symptoms and therefore are complementary. Between them, despite the popularity of nasal endoscopy, radiography can serve as a better planning tool.