<prompt> Threshold for moderate hearing loss -26-40 dB0-25dB41-55 dBNone  <response>: Ans. is c i.e., 41-55 dB o WHO recommended the following classification on the basis of pure tone audiogram.Hearing threshold in better ear average of 500,1000,2000HzDegree of impairment WHO classificationAbilityto understand speech0-25Not significantNo significant difficulty with faint speech26-40MildDifficulty with faint speech.41-55ModerateFrequent difficulty with normal speech.56-70Moderately severeFrequent difficulty even with loud speech71-91SevereCan understand only shouted or amplified speechAbove 91ProfoundUsually cannot understand even amplified speech 