Audio in mobile applications is becoming more prevalent due to advances in mobile devices' audio technologies. Since this is an emerging technology, the interviewer will ask you about it to determine if you are staying up to date on developments in your field and incorporating new technologies and methodologies into your programming. Even if you have not used the audio in your applications, you should be prepared to speak about it and discuss how it enhances the user experience. Even though the interviewer did not ask for examples, you should feel free to provide them to illustrate your answer and make it clearer.