我最近购买了一台安装了 Ubuntu 20.04 的 Dell XPS 13。到目前为止，我的使用体验非常好，但有一件非常奇怪的事情我无法弄清楚。有时登录时会播放声音，但有时却不会。我没有注意到其中的规律，有时它会连续几天不播放。我很困惑，如果能提供任何关于如何解决这个问题的建议，我将不胜感激。我不确定关于我的系统的哪些信息会有帮助，所以请询问。
我设法找到的一个有用的东西是声音文件本身：
/usr/share/sounds/freedesktop/stereo/alarm-clock-elapsed.oga
因为它是一种闹钟声音，所以我认为它可能与默认日历应用程序（与 Google 同步）有关，但在播放声音时我没有看到来自日历的任何通知。
根据@waltinator 的建议，该包似乎是 sound-theme-freedesktop。
$ dpkg -S /usr/share/sounds/freedesktop/stereo/alarm-clock-elapsed.oga
sound-theme-freedesktop: /usr/share/sounds/freedesktop/stereo/alarm-clock-elapsed.oga
$ dpkg -L sound-theme-freedesktop
/.
/usr
/usr/share
/usr/share/doc
/usr/share/doc/sound-theme-freedesktop
/usr/share/doc/sound-theme-freedesktop/README
/usr/share/doc/sound-theme-freedesktop/changelog.Debian.gz
/usr/share/doc/sound-theme-freedesktop/copyright
/usr/share/sounds
/usr/share/sounds/freedesktop
/usr/share/sounds/freedesktop/index.theme
/usr/share/sounds/freedesktop/stereo
/usr/share/sounds/freedesktop/stereo/alarm-clock-elapsed.oga
/usr/share/sounds/freedesktop/stereo/audio-channel-front-center.oga
/usr/share/sounds/freedesktop/stereo/audio-channel-front-left.oga
/usr/share/sounds/freedesktop/stereo/audio-channel-front-right.oga
/usr/share/sounds/freedesktop/stereo/audio-channel-rear-center.oga
/usr/share/sounds/freedesktop/stereo/audio-channel-rear-left.oga
/usr/share/sounds/freedesktop/stereo/audio-channel-rear-right.oga
/usr/share/sounds/freedesktop/stereo/audio-channel-side-left.oga
/usr/share/sounds/freedesktop/stereo/audio-channel-side-right.oga
/usr/share/sounds/freedesktop/stereo/audio-test-signal.oga
/usr/share/sounds/freedesktop/stereo/audio-volume-change.oga
/usr/share/sounds/freedesktop/stereo/bell.oga
/usr/share/sounds/freedesktop/stereo/camera-shutter.oga
/usr/share/sounds/freedesktop/stereo/complete.oga
/usr/share/sounds/freedesktop/stereo/device-added.oga
/usr/share/sounds/freedesktop/stereo/device-removed.oga
/usr/share/sounds/freedesktop/stereo/dialog-information.oga
/usr/share/sounds/freedesktop/stereo/dialog-warning.oga
/usr/share/sounds/freedesktop/stereo/message-new-instant.oga
/usr/share/sounds/freedesktop/stereo/message.oga
/usr/share/sounds/freedesktop/stereo/phone-incoming-call.oga
/usr/share/sounds/freedesktop/stereo/phone-outgoing-busy.oga
/usr/share/sounds/freedesktop/stereo/phone-outgoing-calling.oga
/usr/share/sounds/freedesktop/stereo/service-login.oga
/usr/share/sounds/freedesktop/stereo/service-logout.oga
/usr/share/sounds/freedesktop/stereo/suspend-error.oga
/usr/share/sounds/freedesktop/stereo/trash-empty.oga
/usr/share/sounds/freedesktop/stereo/audio-channel-mono.oga
/usr/share/sounds/freedesktop/stereo/dialog-error.oga
/usr/share/sounds/freedesktop/stereo/network-connectivity-established.oga
/usr/share/sounds/freedesktop/stereo/network-connectivity-lost.oga
/usr/share/sounds/freedesktop/stereo/power-plug.oga
/usr/share/sounds/freedesktop/stereo/power-unplug.oga
/usr/share/sounds/freedesktop/stereo/screen-capture.oga
/usr/share/sounds/freedesktop/stereo/window-attention.oga
/usr/share/sounds/freedesktop/stereo/window-question.oga