Start by describing the symptom and the last action that produced it. Avoid deleting personal data, resetting all settings or reinstalling as a first diagnostic step. Those changes can remove both useful configuration and the evidence needed to explain the problem.
If speech has stopped altogether, start with Recovering from no speech. The presentation checks below assume a working speech route. Backend diagnostics covers further server investigation. For the keys in a particular Aural interface, use its ? Help.
For a problem with otherwise working speech, choose the closest symptom:
For other unexpected feedback, inspect the current item with C-e E or an earlier record through C-e H f h. Use a Presentation Option for unwanted broad optional behaviour, or inspect a narrow exception in Your feedback rules at C-e H r o. For a missing or inappropriate cue, validate the sound pack and inspect overrides. For a saved setup that no longer appears active, compare its Active or Diverged status. Voice distinctions that disappear in some buffers can also come from Voice Lock or explicit face presentation.
A missing custom voice name is a configuration error. Ordinary speech keeps the text by using an unstyled voice and records a diagnostic; it does not invent the missing palette entry. Explain and Aural Doctor can locate that unresolved reference.