Epidemiological study (observational study)

Auditory changes in mobile users: is evidence forthcoming? epidem.

By: Panda NK, Modi R, Munjal S, Virk RS

Published in: Otolaryngol Head Neck Surg 2011; 144 (4): 581-585

Aim of study (acc. to author)

A study was conducted in India to assess the possible changes in hearing function due to chronic exposure to GSM and CDMA mobile phones.

Further details

All participants were taken up for several audiologic investigations including pure-tone audiometry, speech discrimination score, speech reception threshold, impedance audiometry, distortion product otoacoustic emissions (DPOAE), auditory brainstem response (ABR) and middle latency response tests.
Chronic use was defined as using a mobile phone for more than 1 year.

Endpoint/type of risk estimation

changes in hearing function

Type of risk estimation:

prevalence

Exposure

- CDMA
- TDMA
- mobile communications
- mobile phone
- GSM
- personal

Assessment

questionnaire: preferential ear of mobile phone use, total cumulative usage, and average daily use

Exposure groups

Group	Description
Reference group 1	nonusers of mobile phones: controls
Group 2	GSM users
Group 3	CDMA users
Group 4	GSM users, cumulative use: < 3 years
Group 5	GSM users, cumulative use: > 3 years
Group 6	CDMA users, cumulative use: < 3 years
Group 7	CDMA users, cumulative use: > 3 years

Population

Group:
- men
- women
Age: 18–45 years
Characteristics: random hospital visitors and people who responded to an awareness campaign about the health effects of mobile phones
Observation period: July 2008 - December 2009
Study location: India (Chandigarh)
Data source: Department of Otolaryngology Head and Neck Surgery, Postgraduate Institute of Medical Education and Research, Chandigarh
Exclusion criteria: history of ear discharge, previous ear surgery, ototoxic medication, prolonged noise exposure, head trauma, or any systemic disease that might affect hearing

Study size

Type	Value
Participants	183

Other:

63 participants used GSM mobile phones, 62 participants used CDMA mobile phones, 58 participants had never used a mobile phone and served as controls

Statistical analysis method:

Chi-square test
Fisher's exact test
McNemar test

Results (acc. to author)

GSM and CDMA mobile phone users were found to be at a significantly higher risk of having distortion product otoacoustic emissions (DPOAE) absent as compared with controls. They were found to have higher speech frequency thresholds and lower N_a and P_a amplitudes of the middle latency response. Increased changes in the auditory parameters were observed in participants who used their mobile phones more than 3 years compared to persons who used their mobile phone less than 3 years. The damage done was bilateral, with the quantum of damage being the same for both GSM and CDMA.
The authors conclude that long-term and intensive GSM and CDMA mobile phone use might cause damage to cochlea as well as the auditory cortex.

Study funded by

not stated/no funding

Bhagat S et al. (2016): Effects on auditory function of chronic exposure to electromagnetic fields from mobile phones
Gupta N et al. (2015): Effect of prolonged use of mobile phone on brainstem auditory evoked potentials
Sudan M et al. (2013): Cell phone exposures and hearing loss in children in the Danish National Birth Cohort
Balachandran R et al. (2012): Effects of Bluetooth device electromagnetic field on hearing: pilot study
Hutter HP et al. (2010): Tinnitus and mobile phone use
Panda NK et al. (2010): Audiologic disturbances in long-term mobile phone users
Kwon MS et al. (2010): No effects of mobile phone use on cortical auditory change-detection in children: an ERP study
Parazzini M et al. (2009): Effects of UMTS cellular phones on human hearing: results of the European project EMFnEAR
Stefanics G et al. (2007): Short GSM mobile phone exposure does not alter human auditory brainstem response
Parazzini M et al. (2007): Effects of GSM Cellular Phones on Human Hearing: The European Project "GUARD"
Sievert U et al. (2007): [Effects of Electromagnetic Fields Emitted by Cellular Phone on Auditory and Vestibular Labyrinth]
Mora R et al. (2006): A study of the effects of cellular telephone microwave radiation on the auditory system in healthy men
Oktay MF et al. (2006): Effects of intensive and moderate cellular phone use on hearing function
Pau HW et al. (2005): Can electromagnetic fields emitted by mobile phones stimulate the vestibular organ?
Kerekhanjanarong V et al. (2005): The effect of mobile phone to audiologic system
Uloziene I et al. (2005): Assessment of potential effects of the electromagnetic fields of mobile phones on hearing
Sievert U et al. (2005): Can mobile phone emissions affect auditory functions of cochlea or brain stem?
Arai N et al. (2003): Thirty minutes mobile phone use has no short-term adverse effects on central auditory pathways