最后将所获得的环境噪声分贝数与所述音量调节常量之和作为当前手机音量，并用于设置手机的铃声音量。

First, it presets the volume adjustment constant, then tests the environment noise volume by cell phone, and gets the environment noise db.

youdao

最后将所获得的环境噪声分贝数与所述音量调节常量之和作为当前手机音量，并用于设置手机的铃声音量。

First, it presets the volume adjustment constant, then tests the environment noise volume by cell phone, and gets the environment noise db.

youdao