This little piece of code was inspired by the voice aliases featured previously on this site. You need those.

This scrolls through the different voices using the "[" and "]" brackets.

//Aliases you need

alias dev1 				"developer 1"
alias dev0 				"developer 0"

(ungood's Complete Voice Menu Aliases)

//This goes into your autoexec or aliases file, if you need more just make them following the same conventions.

alias v_modnext "v_sel2"
alias v_modprev "v_sel1"

alias v_sel4 "bind E v_medic; bind z v_goright; bind x v_sentryhere; bind c v_goodjob; dev1; echo Vocal Selection Four; wait 100; dev0; wait 30; alias v_modnext v_sel1; alias v_modprev v_sel3"

alias v_sel3 "bind E v_uberready; bind z v_goleft; bind x v_dispenserhere; bind c v_niceshot; dev1; echo Vocal Selection Three; wait 100; dev0; wait 30; alias v_modnext v_sel4; alias v_modprev v_sel2"

alias v_sel2 "bind E v_activateuber; bind z v_moveup; bind x v_teleporterhere; bind c v_help; dev1; echo Vocal Selection Two; wait 100; dev0; wait 30; alias v_modnext v_sel3; alias v_modprev v_sel1"

alias v_sel1 "bind E v_medic; bind z v_gogogo; bind x v_sentryahead; bind c v_battlecry; dev1; echo Vocal Selection One; wait 100; dev0; wait 30; alias v_modnext v_sel2; alias v_modprev v_sel4"

//This goes into your binds

bind "[" 			"v_modprev"
bind "]" 			"v_modnext"
bind "z"			"v_gogogo"
bind "x"			"v_sentryahead"
bind "c"			"v_battlecry"
bind "e"			"v_medic"

//More helpful voice menu keys

bind "KP_MINUS" 	"v_jeers"
bind "KP_PLUS"  	"v_cheers"
bind "KP_SLASH" 	"v_cloakedspy"
bind "KP_DEL"	"v_thanks"
bind "KP_ENTER"	"v_incoming"