iPod strangeness

For many years now I have listened to lectures from The Great Courses on my iPod when taking my walk while I tracked my progress using the fitness app on my iPhone. However, the last time I transferred a new course from iTunes on my computer to my ancient iPod the audio was full of chirps and scratches, even though the sound on my computer was clean. I tried a number of different methods to get clean sound, but without success.

As an alternative I downloaded the Great Course app to my iPhone. With our new and improved data plan, there were no concerns about my streaming the course as did my walks. It has worked out well. I only need to take one device on my walks and the sound quality is great.

Meanwhile I downloaded a music .mp3 file, imported it into iTunes, and transferred it to my iPod. The sound was perfectly clean.

I don’t understand.