Study type: Medical/biological study (experimental study)

Effects of mobile phone exposure on time frequency fine structure of transiently evoked otoacoustic emissions. med./bio.

Published in: J Acoust Soc Am 2007; 122 (4): 2174-2182

Aim of study (acc. to author)

To assess potential subtle changes in cochlear function by measuring transient evoked otoacoustic emissions (TEOAEs) in normal hearing subjects after exposure to electromagnetic fields emitted by GSM mobile phones.

Background/further details

TEOAEs were recorded in 27 healthy young adults before and after 10 min of real exposure or sham exposure.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
Exposure duration: continuous for 10 min
Exposure 2: 1,800 MHz
Modulation type: pulsed
Exposure duration: continuous for 10 min

General information

Half of the participants were exposed at 900 MHz and 1800 MHz, respectively.

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Exposure duration continuous for 10 min
Modulation
Modulation type pulsed
Additional info

GSM

Exposure setup
Exposure source
Setup The phone was positioned in accordance with CENELEC standard EN 50361 by a system consisting of three main parts, all made of non-metallic plastic materials: a headband, an adjustable arm and a phone holder attached to a bracket glued to the battery pack of the phone.
Sham exposure A sham exposure was conducted.
Additional info The procedure was performed twice in a double-blind design on separate days (at least 24 h apart). A 50 Ω resistive load and an open-circuit dummy load were connected to the remote antenna connector of the phone for sham and real exposure, respectively. The effectiveness of the load was confirmed by near field surface scanning of the phone.
Parameters
Measurand Value Type Method Mass Remarks
power 2 W - measured - -
SAR 0.41 W/kg maximum measured - -

Exposure 2

Main characteristics
Frequency 1,800 MHz
Type
Exposure duration continuous for 10 min
Modulation
Modulation type pulsed
Additional info

GSM

Exposure setup
Exposure source
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
power 1 W - measured - -
SAR 0.19 W/kg maximum measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • before exposure
  • after exposure

Main outcome of study (acc. to author)

The data show that there is no measurable effect on transient evoked otoacoustic emissions (TEOAEs) immediately after a 10 min exposure at the maximum power of a GSM mobile phone, neither when TEOAEs were analyzed across the entire frequency range nor when analyzed in their time-frequency fine structure.

Study character:

Study funded by

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