Changes in the hearing threshold using high frequency audiometry in medical personnel exposed to ionizing radiation


  • Pradeep Pooja Department of ENT, Amala Institute of Medical Sciences, Amala Nagar, Thrissur, Kerala, India
  • Karuthedeth Sridevi Department of ENT, Amala Institute of Medical Sciences, Amala Nagar, Thrissur, Kerala, India
  • Anie Melootil Thomas Department of ENT, Amala Institute of Medical Sciences, Amala Nagar, Thrissur, Kerala, India
  • Ariyamparampil Rajagopalan Vinayakumar Department of ENT, Amala Institute of Medical Sciences, Amala Nagar, Thrissur, Kerala, India
  • Pulakkil Arun Department of ENT, Amala Institute of Medical Sciences, Amala Nagar, Thrissur, Kerala, India



High frequency audiometry, Ionising radiation, Sensorineural hearing loss, Ototoxicity


Background: Effect on sensorineural hearing loss by low dose ionizing radiation exposure in radiation workers has been rarely evaluated. A case control study was done among the radiation associated workers and normal subjects.

Methods: The study was done among medical personnels exposed to low dose of ionizing radiation. Age and sex matched healthy control group of subjects were selected. Groups were evaluated by normal otoscopic evaluation; normal tuning fork test and normal standard pure tone audiogram at frequencies from 250 to 8000 Hz. They underwent impedance audiometry, transient evoked otoacoustic emissions, and high frequency audiometry (from frequencies 10000 to 20000 Hz).  

Results: No statistically significant difference was found in the results of impedance audiometry, transient evoked otoacoustic emissions and standard pure tone audiogram from 250 to 8000 Hz between cases and controls. In high frequency range, statistically significant difference was obtained only at 12500Hz (p=0.001) and 16000 Hz (p=0.001). Mean thresholds were higher at all frequencies in cases compared to controls, except at 4000 Hz. A statistically significant correlation was found between duration of exposure and thresholds at 500 Hz (p=0.014) and 10000 Hz (p=0.048). Tinnitus, vertigo, ear block, hard of hearing and loss of appetite were seen more in cases, but was not significant.

Conclusions: Even though using standard pure tone audiometry or high frequency audiometry there was no statistically significant variation in frequencies between cases and controls except at 12500 and 16000 Hz, the mean thresholds were more at almost all frequencies in cases than in controls. Hence a pre placement and periodic high frequency audiometric evaluation in medical personnels with radiation exposure is indicated in future. 

Author Biography

Karuthedeth Sridevi, Department of ENT, Amala Institute of Medical Sciences, Amala Nagar, Thrissur, Kerala, India

Department of ENT, Amala Institute of Medical Sciences, Amala Nagar, Thrissur-680 555, Kerala, India


Kwong DLW, Wei WI, Sham JST, Ho WK, Yuen PW, Chua DTT, et al. Sensorineural hearing loss in patients treated for nasopharyngeal carcinoma: A prospective study of the effect of radiation and cisplatin treatment. Int J Rad Oncol Biol Phys. 1996;36:281-9.

Awwad HK. Radiation Oncology: Radiobiological and Physiological Perspectives. Late reacting tissues: radiation damage to central nervous system. Netherlands: Kluger Academic Publishers; 1990.

Zuur CL, Simis YJ, Lamers EA, Hart AA, Dreschler WA, Balm AJ, et al. Risk Factors for Hearing Loss in Patients Treated With Intensity-Modulated Radiotherapy for Head-and-Neck Tumors. Int J Radiat Oncol Biol Phys. 2009;74:490–6.

Johannessen T, Rasmussen K. Late radiation effects on hearing,vestibular function and taste in brain tumor patients. Int J Radiat Oncol Biol Phys. 2002;53:86–90.

Wichmann A, Jaklevic B, Su TT. Ionizing radiation induces caspasedependent but Chk2- and p53-independent cell death in Drosophila melanogaster. Proc Natl Acad Sci. 2006;103:9952-7.

Fechter LD, Klis SF, Shirwany NA, Moore TG, Rao DB. Acrylonitrile produces transient cochlear function loss andposure to impulse noise. Hearing potentiates permanent noise-induced hearing loss. Toxicological Sci. 2003;75:117-23.

Makitie AA, Pirvola U, Pyykko I, Sakakibara H, Riihimaki V, Ylikoski J. The ototoxic interaction of styrene and noise. Hearing Res. 2003;179:9-20.

Low WK, Tan MG, Chua AW, Sun L, Wang DY:12th Yahya Cohen Memorial Lecture: The cellular and molecular basis of radiation-induced sensori-neural hearing loss. Ann Acad Med Singapore. 2009;38:91-4.

O’Leary stephen. Scott-Brown’s Otorhino-laryngology, Head and Neck Surgery. 7th ed. Great Britain; 2008: 3567-3572.

Chen GD, Fechter LD. The relationship between noise- induced hearing loss and hair cell loss in rats. Hearing Res. 2003;177:81-90.

Training course on safety aspects in research applications of ionizing radiation; Compiled by P. K. Gaur; Radiological physics and advisory division Bhabha Atomic Research Centre, CTCRS, Mumbai.

Sources and effects of ionizing radiation- United Nations Scientific Committee on the Effects of Atomic Radiation; UNESCAR 2008; Report to the general assembly with Scientific Annexes. New York: United Nations; 2010: 32.

Stach B. Glasscock -Shambaugh Surgery of the Ear. 5th ed. 2003: 158-200.

De Seta E, Bertoli GA, Filipo R. High-frequency audiometry above 8 kHz. Comparative results of normative thresholds obtained with a headphone system and a quasi-free-field system. Audiology. 1985;24:254-9.

Fausti SA, Henry JA, Helt WJ, Phillips DS, Frey RH, Noffsinger D, et al. An individualized, sensitive frequency range for early detection of ototoxicity. Ear and Hearing. 1999;20:497-505.

Sivian L, White S. On minimum audible fields. J Acoust Soc Am. 1933;4:288–321.

Biswas A. Clinical Audio-Vestibulometry for Otologists and Neurologists. 3rd ed. Mumbai, India: Bhalani Publishing House; 2002: 44-67.

Kemp DT. Otoacoustic emissions, traveling waves, and cochlear mechanisms. Hearing Res. 1986;22:95-104.

Singh IP, Slevin NJ. Late audiovestibular consequences of radical radiotherapy to the parotid. Clin Oncol R Coll Radiol. 1991;3:217–9.

Rosen S, Plester D. High frequency audiometry in presbyacusis. Archs Otolar. 1964;79:18–32.

Schuknecht HF. Pathology of the Ear. 2nd ed. Malvern, PA: Lea & Febiger; 1993.

National Institutes of Health Consensus Statement. Noise induced hearing loss. NIH Conses Statement. 1990;8:1-24.

Furness D, Hackney C. Scott-Brown’s Otorhinolaryngology, Head and Neck Surgery. 7th ed. Great Britain: Edward Arnold; 2008: 3126-3135.

Cunningham D. Extra high frequency hearing loss and hyperlipidemia. Audiology. 1974;13:470–84.

O’Connor AF. Diseases of the ear. 6th ed. 2002: 453-462.

Wegel R. Physical data and physiology of excitation of the auditory nerve. Ann Otol Rhinol Laryngol. 1932;41:740–79.

Giaccai F. Soglia Audiometrica alle alte frequenze (da 6000 a 24000 Hz). Boll Aud Fon. 1969;18:147–58.

Weinstein BE. Geriatric audiology. New York: Thieme; 2000.

Osterhammel D. High frequency audiometry and stapedius muscle reflex thresholds in juvenile diabetes. Scand Audiol. 1980;9:13–9.

Biswas A. Clinical audio-vestibulometry for otologists and neurologists. 3rd ed. India: Bhalani Publishing House; 2002: 1-23

Fausti S. A system for evaluating auditory function from 8000-20000 Hz. J Acoust Soc Am. 1979;66:1713–8.

Karlidağ T, Kaygusuz I, Keleş E, Yalçin S, Serhatlioğlu SS, Açik Y, et al. Hearing in workers exposed to low-dose radiation for a long period. Hear Res. 2004;194:60–4.

Northern J, Downs M. Recommended High- frequency audiometric threshold levels (8000-18000Hz). J Acoust Soc Am. 1971;52:585–95.






Original Research Articles