Women using some hormone replacement therapies may be putting their hearing at risk, US researchers have claimed.
Hormone replacement therapies come in a number of forms
A study found women using HRT with oestrogen and progestogen had worse hearing than those using oestrogen-only HRT or no HRT at all.
The University of Rochester team gave hearing tests to 124 post-menopausal women aged 60 to 84.
But experts said the link, reported by Proceedings of the National Academy of Sciences, was "far from established".
HRT is used by about one million middle-aged women in the UK to treat the symptoms of menopause, including mood swings and hot flushes.
The majority of women use HRT containing both hormones, as oestrogen-only HRT is usually reserved for women who have had hysterectomies, as it increases womb cancer risk.
HRT has come under close scrutiny in recent years. Research has suggested that HRT using a combination of the hormones oestrogen and progestogen may increase the risk of breast cancer.
And some studies have also suggested a similar risk is associated with the oestrogen-only form.
The treatment has also been linked to heart and dementia problems.
The latest study found the group taking HRT with both hormones had poorer speech perception compared with the other groups.
This problem was also present with background noise and in quiet surroundings, suggesting that problems occurred both in the inner ear and portions of the brain used for hearing.
The report said it was not clear why the effect was found, but it did suggest progestogen may alter the levels of an acid known as GABA in the brainstem and ear auditory system.
Researchers recommended more stringent testing of HRT medications to ensure they do not accelerate sensory losses that may impact upon quality of life and professional abilities.
Lead researcher Robert Frisina said: "Sensory declines in elderly women can significantly interfere with communication abilities, including speech and hearing, professional and economic productivity, family relations and quality of life.
"Therefore increased and improved sensory testing in drug and medication development for our elderly population is warranted."
But David Sturdee, of the Royal College of Obstetricians and Gynaecology, said: "I do not think women in the UK should be too worried at this stage, the link is far from established.
"HRT is almost only given to women aged between 50 and 60 and so this study may be irrelevant.
"HRT is at the centre of a lot of scare stories at the moment and I think the best advice is that each woman should weigh up the risks and benefits for their particular case.
"There may be slight risks, but if the symptoms of menopause are severe each individual has to ask themselves if they would be better being off HRT."