这是因为选择Record类别确保在录音的时候屏蔽提醒音(比如短信提示音)。

This is because choosing the record category ensures that no alerts (such as an incoming text message alert) will sound while the recording is in progress.

youdao

增加来信提示音-新邮件提醒增加来信提示音，让您在第一时间知道新邮件的信息。

Add hint sound for incoming message-New mail reminds you to add hint sounds so that you can get to know the message of new mail at earliest time possible.

youdao

增加来信提示音-新邮件提醒增加来信提示音，让您在第一时间知道新邮件的信息。

Add hint sound for incoming message-New mail reminds you to add hint sounds so that you can get to know the message of new mail at earliest time possible.

youdao