People using mobile phones for more than four years and longer than 30 minutes a day are at risk of developing hearing loss particularly at higher speech frequencies, a study conducted by Post Graduate Institute of Medical Education and Research at Chandigarh has said.

"This hearing loss was more in the dominant ear (ear of use). Presence of fullness in the ears, ear warmth, strange noises in the ear are warning signals which should not be ignored," Dr Naresh Panda, head of the department of Otolaryngology at PGIMER, who along with his team conducted the 18-month long study, said.

He said the aim of the study, which is a preliminary one, done on 100 long term mobile phone users from Chandigarh, was to assess if long term mobile phone use had any adverse effect on hearing and central auditory pathways.

Panda said the study was conducted on people between the age group of 18-45 years and those who were using GSM handsets.

The study group was divided into three categories -- those using mobile phones for 1-2 years, 2-3 years and 3-4 years and above.

Asked if PGIMER was suggesting that people should stop using mobile phones, Panda said it was just a preliminary study and our aim is not to spread panic among the public. All we are saying that people should limit or curtail their usage and take measures like using ear phones.