HD 450.9 S1:1987

Hearing aids - Part 9: Methods of measurement of characteristics of hearing aids with bone vibrator output HD 450.9 S1:1987

Publication date:   Jan 30, 2004

Scope

Defines a method of expressing the input/output ratio as an acousto-mechanical sensitivity level measured on a mechanical coupler according to the second edition of HD 590. Provides a suitable basis for the exchange of information or for direct comparison of the electroacoustic characteristics of hearing aids using bone vibrator outputs. The methods chosen are practical and reproducible and are based on selected fixed parameters.