//паста с uc
g_Hooks.pNetChanHook->Hook(42, Hooks::SendNetMsg);
bool __fastcall Hooks::SendNetMsg(INetChannel* pNetChan, void* edx, INetMessage& msg, bool bForceReliable, bool bVoice)
{
if (msg.GetGroup() == 9) //group 9 is VoiceData то что тебе надо
bVoice = true;
return g_Hooks.oSendNetMsg(pNetChan, msg, bForceReliable, bVoice);
}