Table 8.

Structural Components of Music.

Musical characteristic/number of studies a	Brief description	Examples of how it is tested	Impacts
Pitch and pitch intervals (CI, n = 79) (HA, n = 2) (HL, n = 6)	How high or low a sound is – the frequency Space between two notes. A semitone the distance between a note and its nearest note (in Western music)	Identify which note is higher or lower Pitch direction – up or down Pitch changes played on an instrument or through a computer Pure-tone stimulation (e.g., in a hearing test) CI simulations for TH people compared with CI hearing	HAs programmed for speech often cause distortion, which can affect pitches (Fulford et al., 2011) Pitch is very difficult to identify for most CI users and accuracy is significantly different than among the TH. This may be because of the following reasons: technology is limited (Frosolini et al., 2022). there may be damage to the hearing pathways, particularly for aged people (Frederigue-Lopes et al., 2015; Gu et al., 2017). pitch identification is varied (Alexander et al., 2011; Buyens et al., 2018; Drennan et al., 2015; Gfeller et al., 2007; Gu et al., 2017; Jiam et al., 2019; Jung et al., 2010; Maarefvand et al., 2013; Nimmons et al., 2008) If pitches can no longer be heard correctly: subtleties of music are missed (Kirchberger & Russo, 2015).· it is difficult to identify a melody (Spitzer et al., 2019; Uys & Van Dijk, 2011) or other characteristics of music. the pleasure and social enjoyment of music may be lost (Gfeller et al., 2019) people withdraw from music participation and situations (Gfeller et al., 2019; Lassaletta et al., 2008a)
Melody and melodic contour (CI, n = 75) (HA, n = 2) (HL, n = 5)	Familiar songs Unfamiliar songs	Recognition of familiar music Recognition of the changes in the melody Short sections of music composed for the research (Fuller et al., 2019; Harris et al., 2011). Melody with rhythm removed (Kong et al., 2005; Laneau et al., 2006; Lu et al., 2014; Maarefvand et al., 2013)	Melody identification for CI users was difficult (Leek et al., 2008; Meehan et al., 2017; Nimmons et al., 2008; Spitzer et al., 2021). Melody is best recognized by CI users when it uses high frequencies (Singh et al., 2009).
Melodic harmony (CI, n = 17) (HA, n = 1)	Simultaneous notes, played or sung together	Recognition of the harmonic characteristics – identifying different notes, or voices	Harmony is difficult for CI users to appreciate (Grasmeder & Lutman, 2006). Current technology cannot render harmony accurately (Gfeller et al., 2005; 2019). Harmony and dynamics are important for enjoyment and emotion (Camarena et al., 2021; Gu et al., 2017).
Timbre (CI, n = 63) (HA, n = 1) (HL, n = 4)	What makes voices or instruments different from each other	Ability to pick out individual voices or instruments within complex music Same melody played on different instruments or at a different pitch	Timbre is important for segregating sound in multi-instrument contexts (Galvin et al., 2008). Music often becomes unpleasant noise. CI users have difficulty with timbre perception (Alexander et al., 2011)
Instruments (CI, n = 72) (HA, n = 2) (HL, n = 1	Piano, guitar, flute, trumpet, etc.	Recognition of a solo instrument	Instruments within the same family (e.g. a violin or cello; trumpet or trombone) were often difficult to identify (Galvin et al., 2008). Decay of an instrument (the time the vibrations can be heard) are shortened with a CI (Grasmeder & Lutman, 2006) Music from lots of instruments just sounds like noise (Gfeller et al., 2019)
Rhythm (CI, n = 57) (HA, n = 1) (HL, n = 1)	Beat, time (meter) of music	Recognition of a rhythm, melodies played with different rhythms	Rhythm is reported as the characteristic CI users can best identify (Cooper et al., 2008; Jung et al., 2010; Lassaletta et al., 2008a; Magele et al., 2022). Rhythm helps identify melodies (Peterson & Bergeson, 2015)

^aSome studies tested more than one music characteristic.