new SV_GSTREAM:gstream = SV_NULL;
new SV_LSTREAM:lstream[MAX_PLAYERS] = { SV_NULL, ... };

public SV_VOID:OnPlayerActivationKeyPress(SV_UINT:playerid, SV_UINT:keyid) 
{
    // Attach player to local stream as speaker if 'B' key is pressed
    if (keyid == 0x42 && lstream[playerid]) SvAttachSpeakerToStream(lstream[playerid], playerid);
    // Attach the player to the global stream as a speaker if the 'Z' key is pressed
    if (keyid == 0x5A && gstream) SvAttachSpeakerToStream(gstream, playerid);
}

public SV_VOID:OnPlayerActivationKeyRelease(SV_UINT:playerid, SV_UINT:keyid)
{
    // Detach the player from the local stream if the 'B' key is released
    if (keyid == 0x42 && lstream[playerid]) SvDetachSpeakerFromStream(lstream[playerid], playerid);
    // Detach the player from the global stream if the 'Z' key is released
    if (keyid == 0x5A && gstream) SvDetachSpeakerFromStream(gstream, playerid);
}


public OnPlayerConnect(playerid)
{
    // Checking for plugin availability
    if (SvGetVersion(playerid) == SV_NULL)
    {
        SendClientMessage(playerid, -1, "Could not find plugin sampvoice.");
    }
    // Checking for a microphone
    else if (SvHasMicro(playerid) == SV_FALSE)
    {
        SendClientMessage(playerid, -1, "The microphone could not be found.");
    }
    // Create a local stream with an audibility distance of 40.0, an unlimited number of listeners
    // and the name 'Local' (the name 'Local' will be displayed in red in the players' speakerlist)
    else if ((lstream[playerid] = SvCreateDLStreamAtPlayer(40.0, SV_INFINITY, playerid, 0xff0000ff, "Local")))
    {
        SendClientMessage(playerid, -1, "Press Z to talk to global chat and B to talk to local chat.");

        // Attach the player to the global stream as a listener
        if (gstream) SvAttachListenerToStream(gstream, playerid);

        // Assign microphone activation keys to the player
        SvAddKey(playerid, 0x42);
        SvAddKey(playerid, 0x5A);
    }