How do I type in IPA?

You can get access to the SIL repository following these instructions, then get the latest versions of kmfl-ibus and the IPA Keyboard package from the Ubuntu Software Center (searching for "kmfl" it should be one of the top results). Don't forget to log out and in.

For future reference, this page shows IPA keyboards for Windows, Linux, and Mac.

From the keyboard logo in your upper toolbar, which is hopefully there now, choose preferences, input method, select an input method, other, and IPA Unicode KMN, then click Add. You can choose how you switch from and to IPA from the "general" tab.

Good luck! Good luck!

You can also use a virtual keyboard such as Onboard. It shows a small clickable keyboard on your screen. I wrote an IPA layout for Onboard which is still in beta but already functional:

Disclaimer : I am the author of the IPA layout.

Try this Debian package from this site. You might need to get ibus-kmfl installed first. This page has a repository.

There is an input method based on X-SAMPA, which is available for the IMEs IBus and Fcitx (as well as UIM and RIME).

An IME (input method editor) is commonly used for inputing ordinary language scripts with large numbers of characters (like Chinese and Japanese), and is a natural solution for IPA as well. X-SAMPA is an ASCII based encoding of IPA and hence easily typed on an ordinary QWERTY keyboard. The IME will convert the ASCII character sequences to the appropriate Unicode character as you type.

You can get it in Ubuntu 16.04 by installing the package "ibus-table-ipa-x-sampa" (if you use IBus) or "fcitx-table-ipa-x-sampa" (if you use Fcitx). You will have to set up one of the IMEs if you aren't using one already, and will probably have to add "IPA-X-SAMPA" to your input method list (which should include your default keyboard as well as input methods or keyboards for any other languages you use).

I've tried the Fcitx version, and it seems to work as intended.

This could be a good alternative to to the "IPA Unicode KMN" keyboard described in xanxerus's answer, which works with IBus and SCIM, but not Fcitx. This is particularly relevant to Kubuntu, since recent versions (like 16.04) use Fcitx by default. Additionally, it requires no additional repositories to be added.