Table 1.

Overview and description of CAFPAs.

Functional aspects	CAFPA	Description
Hearing Threshold	CA1 CA2 CA3 CA4	The CAFPAs CA1-CA4 refer to the hearing threshold at increasing frequencies. Hearing threshold refers to the minimum sound level that is required to hear a sound. It is indicated as the threshold at which a sound is detected at least 50% of the time. The hearing thresholds are given in decibels of the hearing level (dB HL) for given frequencies in comparison to the normal population. Values between 0 and 20 dB HL are considered to be within the normal range, whereas increasing dB HL values correspond to increasing hearing loss for the given frequencies (24).
Suprathreshold deficits	CU1 CU2	These components refer to deficits at levels above the threshold (24) for lower (CU1) and higher frequencies (CU2). Even if hearing threshold levels are within the normal range, deficits may still be present in the suprathreshold range, e.g. with deficits in speech recognition (25).
Binaural hearing	CB	Binaural hearing reflects processes taking place in the central nervous system, which enables hearing with two ears simultaneously (24, 26). On the one hand, this entails the ability to perceive different signals that reach the two ears as one, termed binaural fusion (24). On the other hand, binaural hearing allows spatial hearing and sound localization (26, 27).
Neural processing	CN	This CAFPA broadly defines the involvement of neural components in the hearing process, such as the cochlear and auditory neurons (24).
Cognitive components	CC	Cognitive components play a role in hearing deficits. Studies have widely indicated a correlation between age-related hearing loss and cognitive decline, even though the causal mechanisms remain unclear (28). Cognitive decline may reduce available cognitive resources for auditory processing. Conversely, reduced auditory input caused by hearing loss may lead to a degradation of inputs to the brain, causing cognitive decline. In any case, a strong association between cognitive measures and hearing loss has been found (29).
Socio-economic status	CE	This CAFPA contains information regarding the socio-economic status of an individual, which is a combined measure of economic and social status, found to be positively associated with better health (30).