JEDict can load audio files containing pronunciation of English or Japanese words. JEDict looks for sound files inside ~/Library/JEDict/audio/ directory.
English word pronunciation files should be stored in ~/Library/JEDict/audio/eng/ directory. Optionally they may be distributed among ../a to ../z sub-directories according to first word letter. Sound file name should correspond to pronounced word.
Sound files for Japanese words should be stored ~/Library/JEDict/audio/jpn/ directory with file names corresponding to Japanese word. Allowed extensions for sound file are .mp3, .wav or no extension. First JEDict searches for word as it was typed, then it looks for its hiragana transcription and finally or its hiragna or it tries to find romaji transcription.
Each time JEDict finds out a word in dictionary, it looks for corresponding sound file. If file is available, you will see 'speaker' button close to search field.