The age-related hearing loss compensation function applies a frequency dependent gain, based on median hearing thresholds published by the International Standards Organisation (ISO 7029). This boosts the higher audio frequencies that become more difficult to hear with age.
The compensation will not be perfectly accurate, because these are median values instead of tailored specifically to the listener, and because of non-linearities in human hearing, but should be a useful first approximation.
To use this, go to the "Hearing loss comp" submenu to set your age and gender and to toggle this feature on or off.
If you use a hearing aid, this should already apply the relevant compensation and so the WOLFWAVE hearing loss feature should not be required.