There are some miniature voice recorders available in the market. you can buy one of them and record the audio. Then you can transfer them to PC and convert the audio to text using some converters like voice to text software.
You can find details regarding the voice recorder here http://www.spy3k.fr/Mini_Dictaphone_Espion.html
Steno is India’s first voice-to-text legal e-buddy that helps your voice type legal documents for free. That is, Steno has been designed with AI to automatically change audio waves to a text online when you talk to it. This web application has been specifically assembled with legal maxims and punctuations, therefore it can identify legal terminologies accurately and give you a fast, free and accurate documenting experience online.