Their study used irrelevant speech and articulatory suppression to test whether time estimation is affected during a task condition or phonological load.
Most research demonstrates articulatory suppression by requiring an individual to repeatedly say an irrelevant speech sound out loud while being presented with a list of words to recall shortly after.
Specifically, researchers wanted to look at the differences between simultaneous interpreting and articulatory suppression as they relate to working memory.
This class of sounds is difficult to characterise phonetically; from a phonetic standpoint, there is no single articulatory correlate common to rhotic consonants.
