WHIS: Wadai (or Wakayama University) Hearing Impairment System
This system allows normal hearing (NH) listeners to experience the difficulty that hearing impaired (HI) listeners have in everyday life.
You can set hearing level (e.g. average of 80 year-old listener) and the degree of healtiness of OHC (outer hair cell).
You need to calibrate sound pressure level when using WHIS.
The best practice is to use a reliable sound level meter and an artificial ear (e.g. B&K). But it may costs more than $10,000.
For class room training, you may use alternative equipment, "ChomeJig" which we developed about $30.