What?
Functionality to edit/affect how voice works on clientside (per client).

1. SetVoiceVolumeTarget [INCOMING]

• Allow to control voice volume level of other clients (clientside effect only)

This means that clientA will be able to change the INCOMING volume of clientB.
This allows modders to either change voice volume for certain players via script, or introduce volume levels for players to set manually.
Currently (1.08) player can only adjust the outgoing volume (with SetVoiceLevel).

2. SetVoiceEffectTarget [INCOMING]

• Allow to control the voice effect of other clients (clientside effect only)

This means that clientA will be able to change the INCOMING voice effect of clientB

These could allow clients to hear the same player in different ways.
This can be useful for clientside voice occlusion and other effects.