REALLY?

LITTLE ROCK — Why do many older people have difficulty hearing conversations, yet music in restaurants is too loud?

Age-related hearing loss, called presbycusis, is characterized by loss of hair cells in the base of the cochlea, or inner ear, that are attuned to capture and transmit high-frequency sounds, said Dr. Anil K. Lalwani, director of otology, neurotology and skull-base surgery at New York-Presbyterian Hospital/Columbia University Medical Center.

Loss of high-frequency hearing leads to deterioration in the ability to distinguish words in conversation. Additionally, any noise in the environment leads to even greater loss in clarity of hearing.

“Contrary to expectation, presbycusis is also associated with sensitivity to loud noises,” Lalwani said. “This is due to a poorly understood phenomenon called recruitment.”

Normally, a specific sound frequency activates a specific population of hair cells located at a specific position within the cochlea. With hearing loss, this specificity is lost, and a much larger population of hair cells in the adjacent areas is “recruited” and also activated, producing sensitivity to noise.

“Patients with presbycusis perceive an incremental increase in loudness to be much greater than those with normal hearing,” he said. “This explains why the elderly parent complains that ‘I am not deaf!”’ when a son or daughter repeats a misheard sentence.