Table A2.

Parameters assessed by the included studies. (a) Studies reporting on intracochlear electrical stimulation; (b) Studies reporting on extracochlear electrical stimulation.

(a) Studies Reporting on Intracochlear Electrical Stimulation
Authors, Year	Stimulation Type (CI, RW)	AC/DC	1. Electrode Location	2. Current Level	3. Pulse Rate	4. Polarity	5. Amplitude Modulation
Arts et al., 2016 [51]	CI	AC	●	●	●	●	●
Arts et al., 2015 [82]	CI	AC	●	●
Chang et al., 2012 [83]	CI	AC	●	●	●
Dauman et al., 1993 [57]	CI	AC	●	●	●
Kloostra et al., 2020 [72]	CI	AC	●	●	●
Olze et al., 2018 [64]	CI	AC			●		●
Punte et al., 2013 [65]	CI	AC	●
Rothholtz et al., 2019 [71]	CI	AC	●	●	●
Rubinstein et al., 2003 [67]	CI (3), RW (11)	AC	●	●	●
Zeng et al., 2011 [70]	CI	AC	●	●	●
(b) Stimulation Reporting on Extracochlear Stimulation
Authors, Year	Stimulation Type (OW, PM, RW, CI)	AC/DC	1. Electrode Location	2. Current Level	3. Pulse Eate	4. Polarity	5. Amplitude Modulation
Aran et al., 1981 [77]	RW, PM	AC, DC	●	●	●	●
Cazals et al., 1978 [75]	RW (13), PM (3)	AC, DC	●	●	●	●
Cazals et al., 1984 [78]	RW	DC+		●
Daneshi et al., 2005 [56]	PM, CI (control)	AC		●	●
Di Nardo et al., 2009 [58]	PM	DC+		●	●
Graham et al., 1977 [74]	PM	AC		●	●
Hazell et al., 1993 [76]	RW	AC		●	●		●
House et al., 1984 [73]	PM	AC			●		●
Ito et al., 1994 [87]	PM	NI
Konopka et al., 2001 [60]	PM	AC		●	●
Konopka et al., 2008 [59]	PM	DC+		●
Mahmoudian et al., 2013 [62]	PM	AC		●	●
Mahmoudian et al., 2015 [61]	PM	AC		●	●
Matsushima et al., 1994 [85]	PM	AC		●
Matsushima et al., 1996a [63]	PM	AC		●
Matsushima et al., 1996b [55]	PM	AC
Okusa et al., 1993 [86]	PM	AC			●
Péan et al., 2010 [79]	OW	AC		●	●	●
Portmann et al., 1979 [80]	RW (11), PM (7)	AC, DC	●	●	●	●
Portmann et al., 1983 [81]	RW, PM	DC+		●
Rothera et al., 1986 [66]	PM	AC, DC		●	●	●
Rubinstein et al., 2003 [67]	CI (3), RW (11)	AC	●	●	●
Watanabe et al., 1995 [68]	PM	AC		●
Wenzel et al., 2015 [69]	RW	AC		●	●
Carlson et al., 2020 [84]	PM	AC	●	●	●	●

AC: alternative current; CI: cochlear implant; DC: direct current; DC+: anodic direct current; OW: oval window; PM: promontory; RW: round window.