Bonjourin

An interesting topic, presented [in French] in a fun way:

[If you have trouble with the Facebook embedding, try this YouTube version.]

Here are some background papers by Anita Berit Hansen, who is featured in the second half of the interview:

A. B. Hansen, "The Covariation of [ə] with Style in Parisian French: An Empirical Study of 'E Caduc' and Pre-Pausal [ə]", PPoSpSt-1991.

A. B. Hansen, "Les voyelles nasales du francais parisien moderne: Aspects linguistiques, sociolinguistiques et perceptuels des changements en cours", 1998.

A. B. Hansen & M-B. M. Hansen, "Le [ə] prépausal et l'interaction", Structures linguistiques et interactionnelles dans le francais parlé: actes du colloque international, Université de Copenhague 2003.

And also:

Julien Eychenne, "The emergence of prosodic schwa in French", BIDE 2005.

The original discussion of pre-pausal schwa as a prosodic intrusion in French:

François Dell, Les règles et les sons: Introduction à la grammaire générative, 1973.

Perhaps I'm not searching right, but I had a hard time finding digitally-accessible discussions of this (and related) phenomena.