This is considered by some scholars (such as P. Aubry) to be a result of Turkish influence, although others (such as R. P. Decevrens) consider it to be of great antiquity and use it as evidence in favor of a more rhythmic interpretation of Gregorian chant.
This is perceived by some (like P. Aubry) as due to Turkish influence, whereas others (such as R. P. Decevrens) consider it ancient and use it to advocate for a more rhythmic approach to interpreting Gregorian chant.