Cell Phones May Cause Hearing Loss
But Some Experts Still Not Convinced
Sept. 19, 2007 -- Long-time mobile phone users who talk more than an hour a
day on the devices may be may be more likely to have high-frequency hearing
loss, researchers say.
"Our intention is not to scare the public," says Naresh K. Panda,
MS, DNB, chairman of the department of ear, nose, and throat at the Post
Graduate Institute of Medical Education and Research in Chandigarh, India, and
researcher for the study. The study, he tells WebMD, is preliminary and
small. "We need to study a larger number of patients."
He presented the findings Wednesday at the annual meeting of the American
Academy of Otolaryngology -- Head and Neck Surgery in Washington.
His team found that people who had talked on cell phones for more than four
years and those who talked more than an hour daily were more likely to have
these high-frequency losses. These losses can make it difficult to hear
consonants such as s, f, t and z, making it hard to understand words.
But another hearing expert familiar with the study says there is as yet no
cause for alarm.
Hearing Loss Study
Panda and his colleagues evaluated 100 people, aged 18 to 45, who had used
mobile phones for at least a year, dividing them into three groups according to
length of use. One group of 35 had used phones for one to two years; another
group of 35 had used them for two to four years, and a group of 30 had used
them for more than four years.
"We asked them if they had been using the phones less than 60 minutes or
more than 60 minutes per day," Panda tells WebMD. They compared the phone
users with 50 people who had never used cell phones and served as a control
group. The study was conducted in India.
Those who used the mobile phones for more than four years had more hearing
loss in high-frequency ranges in their right ear, the ear most held the phone
to, than those who used the mobile phone for one to two years.
"When we compared high-frequency thresholds (the level at which the
sound is first detected) between the one- to two-year [users] and more than
four years; there was a significant difference in the thresholds between these
two groups," he says.
One- to two-year users had a 16.48 decibel loss in the high-frequency range,
he says, while those who used the phones more than four years had a 24.54
That decrease in hearing over a relatively brief period may not be
noticeable to mobile phone users but would be of concern to a hearing expert,
says Andy Vermiglio, AuD, a research audiologist at House Ear Institute in Los
Mobile phone users who had symptoms such as a warm sensation, fullness in
the ears, or ringing were more likely to have the high-frequency hearing loss,
Panda also says.
Long-term mobile phone use may result in inner ear damage, Panda speculates.
And symptoms such as ear warmth or fullness could be early warning signs of