Figure 5: The recruitment hypothesis can be conceptualized as a loss of the active cochlear amplifier. S-shaped curved line : With the active cochlear amplifier the amplitude increase (y) of the basilar membrane in the inner ear needed to perceive changes in loudness requires a relatively large increase in sound level (x1) since the curve is non-linear [342]. Straight line : Without amplification (passive inner ear) the curve is linear. For the same amplitude increase (y) a smaller sound level increase (x2) is required [343]. This is termed recruitment. Loss in dynamic range is accompanied by loss in frequency selectivity and thus loss in speech discrimination (loss of discrimination) (modified from Preyer and Gummer 1996) [79].