When using an authentic audio or video it is important to use only ‘native speakers'.

When using an authentic audio or video it is important to use only ‘native speakers'.

I wholeheartedly disagree with this, as there are lots of studies that show that ELL students who practice with one another tend to progress in ways that interacting with native speakers cannot. In my own classes, I try to use audio with non-native speakers.

I usually teach students whose goal is to eventually study in the US, and if they don't practice understanding a variety of accents, they will probably run into a few surprises. I have some students who have trouble understanding different accents, and it's important to practice this so that they are able to interact with people from a variety of different backgrounds (whom they will find if they travel to most countries where English is the primary language).