By Randolph E. Schmid, Associated Press | September 5, 2006

WASHINGTON -- Older women taking certain hormone replacement therapy may suffer hearing damage, scientists report.

A study of 124 postmenopausal women found that those taking hormone replacement therapy that included progestin had poorer speech understanding than women not taking hormones or those using estrogen only.

The findings, by a team led by Dr. Robert D. Frisina at the University of Rochester Medical Center in Rochester, N.Y., are reported in today's issue of Proceedings of the National Academy of Sciences.

The team previously had reported indications of hearing problems associated with hormone therapy and their new study says progestin is the likely culprit.

The research found problems in the inner ear and in some measures of brain function affecting hearing in women using hormone therapy with progestin, Frisina said in a telephone interview.

Because hearing problems can affect quality of life, he urges increased hearing testing for women using this therapy , especially those who already have some hearing loss .

``We feel this should be added to the list of possible side effects," Frisina said.

His next step is to look at women who stop using progestin and see if the hearing damage is reversible.

Not everyone is convinced of the findings, however.

``The jury is still out" on the effects of hormone replacement therapy on hearing, says Dr. Karen S. Helfer of the University of Massachusetts at Amherst.

Helfer, who said she has done similar research on a smaller scale, said, ``There are a number of reasons to suspect that [hormone replacement therapy] would have either a positive or a negative effect on hearing. Subtle differences in auditory abilities can be demonstrated during different phases of the menstrual cycle."

Dr. Wendy S. Klein of Virginia Commonwealth University Medical Center said the study included only 32 women treated with progestin, which she said makes it difficult to generalize from the results. Thirty were on estrogen only; 62 were not using hormones.