Forgive me if this is too basic, but I searched the Sonar manual, this forum and Google for the answer. This is my first time importing audio into a project. It's just an 11 second mp3 of a timpani roll. The file loads into the audio track, but I don't hear any audio. I auditioned it first & the file is good, so I thin k there's some setting or formatting thing I'm overlooking, perhaps? I got the file by using an online utility to convert a YouTube video of it to mp3, so maybe I'm losing something needed or gaining something harmful in that process. Thank you for your assistance.

Have you tried previewing the file in Sonar's Browser?
https://www.cakewalk.com/Documentation?product=SONAR%20X2&language=4&help=Tutorial2.2.html
 

Do you see any activity in that track`s playback meters?  If so, you might want to ensure that the the output is correctly routed, and that if it is routed to a bus (for example, the Master bus), to make sure that that bus is not muted or that the faded is not completely down.

It has been reported several times here that MP3s including metadata (pictures, text) don't work in SONAR.
An audio track can only handle audio, so the metadata should be removed first.
A video-to-MP3 conversion sure could include some hooks. I've never done it so I can't help, sorry.

Thanks to all for the help (ja kiitos Kalle). I'll try your suggestions and report back.