dialing tone

例句：

1. 1.The phone company's dialing tone is very clear and easy to understand.
   电话公司的拨号音调非常清晰，易于理解。
2. 2. When dialing a number, the dialing tone is important for the connection.
   拨号时，拨号音调对于连接很重要。
3. 3.The dialing tone can be used to indicate different types of calls.
   拨号音调可以用来表示不同类型的呼叫。