A recording studio captures a voice so it can be played back. Dream books read it as the wish to be heard clearly, and as the unease of hearing yourself as others hear you.
Where in your waking life have you met something like this lately?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.