Assuming your team mates use sound when they are playing AO, and have the Voices activated, you can use default AO voice pack commands, or alternatively install one you have made yourself or that someone has made for you and say phrases in certain channels.
Accessing the settings:
The voice command preferences can be found under F10 -> Audio -> Voices
Preferences Panel on the Audio Tab
As you can see, within this panel you can turn the voices on or off, adjust the volume at which you can hear voices, choose which voice you would like to be heard as and select which channels you would like activated.
To use the default voice settings:
You can either type these commands each time you want to use them or set up macros so you can put them on your quickbar.
You will indicate that you agree.
You will indicate that you don't agree.
You will indicate that you need healing.
You will indicate that you need assistance.
You will indicate that enemies are incoming.
You will indicate that you think it is time to retreat.
So, to hear the voices ingame you must have the channel activated that they are being used on. If you do not have it activated you will purely see a text output when one is triggered by another player.
It is possible to customize the voice files, you will find one already made here at AO Universe in our Voice Pack section.
Making your own:
If you wish to customize your own voice pack, firstly you really should back up the existing voices folder, this will make things much easier to restore the originals if you need to without the need to go through a complete new installation process.
The voice files, and their corresponding text files, can be found in this folder:
When you enter a command, the client will check for the corresponding text file within this location, and subsequently the corresponding .wav file to play.
Basically, if you wish to create your own, you must have a .txt with a .wav with exactly the same overall name apart from the extension type. For example, if you wish to make a voice command that is different for each character on your account. Then you will need to rename each file depending perhaps on that character's name:
character_heal_01.txt with a corresponding character_heal_01.wav
Then, when you are ingame you just need to type /voice character_heal
The client will search for the first appropriate match to this command and make it sound ingame. The variations and possibilities are endless, if you want to make separate voice packs for Solitus, Nanomage, male, female.. whatever, you can. However you should always ensure that the name includes the _01 before the file extension. Should you forget, the AO client will tell you that "You do not have that voice file installed".
If you do make your own voice pack and want to use it ingame, please be aware that unless other players have your voice pack installed they will not hear your command, only see the text it generates.