The effects of vocational noise exposure on hearing aid battery subjective life.

This study examined the effects of vocational training noise on subjective battery life and on battery current drain, in 5 different class B hearing aids worn by students at a school for the deaf. Each S used a mercury battery in the morning in an average listening school environment with a 2-hr period of vocational noise exposure included, and another battery in an average school listening environment from after lunch to bed time. Voltage measurements and usage hrs were recorded until S reported the battery was not working. There were no mean differences in subjective battery life nor in recorded voltage drop between the two conditions. Battery life in 2 batteries exposed to vocational noise may have been extended due to a 10-day rest period during the spring break for these 2 students.