If we use a land - line phone we should use the type that has a cord connecting the earpiece to the main body of the phone . and if we use a cordless home phone or any type of portable phone we should use an earpiece with it 室内电话，也要使用电话听筒与电话主机之间有电线连接的电话机，如果使用无线电话或任何款式的携带式电话，最好都能用耳机收发电话。
