#include <sdktools>

#define MAX_STR_LEN 128

new UserMsg:g_umSendAudio;

...

public OnPluginStart()
{
    // Um: RadioAudio
    if ((g_umSendAudio = GetUserMessageId("SendAudio")) != INVALID_MESSAGE_ID)
  HookUserMessage(g_umSendAudio, UserMsgSendAudio, true);
    else
  SetFailState("GetUserMessageId for SendAudio");

    HookEvent("round_end", Round_End, EventHookMode_Pre);
}
// No sound
public Action UserMsgSendAudio(UserMsg:msg_id, Handle:bf, const players[], playersNum, bool:reliable, bool:init)
{
    char msg_str[MAX_STR_LEN];

    BfReadString(bf, msg_str, sizeof(msg_str));

    if (StrEqual(msg_str, "radio.go", false) || StrEqual(msg_str, "radio.locknload", false) || StrEqual(msg_str, "radio.moveout", false) || StrEqual(msg_str, "radio.letsgo", false))
  return Plugin_Handled;

    return Plugin_Continue;
}

public Action Round_End(Event event, char[] name, bool B_DontBroadcast)
{
    for (new i = 1; i < MaxClients; i++)
    {
  if (IsClientInGame(i) && !IsFakeClient(i))
  {
   StopSound(i, SNDCHAN_STATIC, "radio/ctwin.wav");
   StopSound(i, SNDCHAN_STATIC, "radio/terwin.wav");
  }
    }
}