CI/s	Cochlear implant/s—implanted prosthesis of any brand that bypasses the damaged portion of the cochlea. When the external processor is connected, it provides a sense of sound [18,92]
HA/s	Hearing aids
HL	Hearing loss/hearing impairment—any level of loss, one or both ears, caused by any aetiology, treated or untreated
LDA/s	Late-deafened adults, typical hearing people who experienced HL in later life
QoL	Quality of life—including aspects of social wellbeing, emotional and physical health, communication, autonomy, and social integration
CIQoL	Cochlear Implant Quality of Life [51]
Gold-MSI	Goldsmith’s Musical Sophistication Index [55]
MuRQoL	Music-Related Quality of Life [93]