短语词组短語Vacant Number Tone 空號音change number tone 用戶號改變音No Such Number Tone 空號音changed number tone 用戶號改變音Number Unobtainable Tone [通信]空號音Number Check Tone 號碼檢查音Number Changed Tone 號碼已更改音number unobstainable tone 空號音 返回 tone number