Table 4.

Summary of recommendations on insertion speed in the literature.

Author, Year	Temporal Bone Models	Type of Insertion	Calculated IS (mm/s)	Time of Insertion (s)	Recommended IS (mm/s)	Conclusion
Rau 2010 [10]	acrylic glass	M	-	20	0.5	The insertion forces appear to increase if a CI is inserted slower than 0.5 mm/s.
Kontorinis 2011 [8]	polytetrafluoroethylene (Teflon)	H	mean 1.60 range 0.7–2.75	-	“slow and stable”	High insertion speeds cause significant increase in the forces.
Rajan 2012 [4]	in vivo retrospective analysis	H	-	-	0.25	A slow electrode insertion speed reduces the occurrence of insertion resistance and increases hearing outcomes.
Pile 2013 [22]	cadaver	M	0.5–3	-	1	Mean insertion forces do not significantly reduce after insertion speeds exceed 1 mm/s.
Todt 2014 [6]	synthetic	M	-	-	0.25	Direct correlation between insertion speed and fluid pressure.
Kesler 2017 [19]	cube of bone surrogate material	H	0.86 ± 0.32	-	-	CI electrode insertion at 25 mm/s is not feasible for human operators.
Hugl 2018 [11]	f-polytetrafluoroethylene (PTFE)	M	2.8–0.045	-	“as slow as possible”	A slow electrode insertion speed reduces the occurrence of insertion resistance.
Snels 2018 [20]	human and synthetic	H, M	-	-	-	Slow insertion increases hearing preservation.
Aebischer 2021 [3]	epoxy resin	M	0.33	78	-	Slower and non-constant rate insertions decrease forces.

H, human; M, mechanical.