his young brother once wrote to him in 2005,and 〔hasn't been heard from〕sincehear from意思是收到,那么为什么要用been heard from的被动句?

Question

his young brother once wrote to him in 2005,and 〔hasn't been heard from〕since
hear from意思是收到,那么为什么要用been heard from的被动句?

Answer 1

这句话的意思是说,自从2005年的那封信后,他弟弟就没消息了.
been heard from 表示被听到 主语是：his young brother
如果这里听的主语是him ,在中文里,他是主语,“他再也没有弟弟的消息（再也没有听到弟弟的消息）,自从2005年收到一封信后” ,那么英文就该表示为：
he hasn't heard from his young brother since ...