I've encountered on my iPod (latest gen, 64 gb) audio dropping out twice recently. Listening to music/podcasts, the audio will just cut out. System indicates the audio should still be playing, but no sound. Using iPod headphones with remote. Remedy was to unplug/reconnect headphones, but very annoying.
audio drops
I get the same problem but without even having any headset plugged in. The audio cuts out in different apps. The only way I was able to restore audio was to restart my iPhone 6+.
I haven't figured out what is the cause as it happens so frequent that it isn't just one app. Even Apple's native apps like iMessages the audio cuts out.