If I were to send an email or letter to the company that owns a movie asking for permission to use soundbites can I assume yes if they do not respond?

Me and my friends want to make a soundboard apps for Android, and do not want to step over copyright laws. They would only be a few seconds worth of clips, but I am assuming they would still be protected under copyright. I feel like the only way around this is to ask for permission, but I am curious how we can proceed if they do not respond. Thanks for your time! A soundboard would consist of around 20 different buttons that when pressed play a sound clip from a movie or a song.