You can reduce the MP3 audio file size in Text Speaker by selecting the proper values for Audio Frequency, Bitrate and Audio quality from the Audio Properties dialog.
[image: MP3Properties.png]
If you have selected high values for quality, bitrate and frequency, then the output MP3 file will be large. Try choosing a lower bitrate. Please note that the size of the MP3 file will also depend on the size of E-book which you are converting.