Through working extensively with second language professionals and their families in one-on-one classes and group business pronunciation and communication courses since 2003, it quickly became evident that:

• Students were misinterpreted by colleagues and bosses not only for what they said but for who they were based on some suprasegmental features.
• Students were misjudging native speakers meaning, intention, and culture based on suprasegmental features.
• Pronunciation differences, especially related to suprasegmentals, were affecting their ability to leverage their skills, advance their careers, and communicate what they really meant to native English speaking loved ones.
• Students were subconsciously choosing not to take on pronunciation features because of L1 interference and identity concerns.
• Pronunciation and cultural training related to suprasegmentals seemed to help students interpret native speakers and communicate more effectively personally and professionally.

These observations changed the way I taught. I began to wonder-

• Are my observations accurate?
• Is the way I'm teaching effective?

This lead to the study German and American Interpretations of Sincerity in American English.

Here is a quick summary:

Suprasegmental pronunciation features communicate meaning, emotion, attitude, and intention, but the degree to which this is universal across cultures or specific to cultures is still debated. This study investigates the degree of difference between native American English speakers’ and native German speakers’ interpretations of degrees of sincerity in American English speech. It also considers to what degree pronunciation training designed to raise awareness of sincerity-oriented suprasegmental pronunciation features and the sociolinguistic reasoning behind their use might improve German speakers’ interpretation abilities. A group of 19 native German speakers (16 university students and 3 non-university professionals) and a U.S. university class of 14 native English speakers listened to twenty emotionally-neutral pseudosentences and rated them as sincere or insincere based on suprasegmental features.  Both groups listened a second time and rated them on a 5-point Likert scale of degrees of sincerity. German students then participated in a video lesson regarding the relationship between suprasegmentals and sincerity. They then re-listened to the twenty utterances twice and re-rated them in the same way as before. The results indicated that prior to training, native English speakers had an in-group advantage, being a large degree more effective in interpreting sincerity in American speech. German improvement following pronunciation training, while not very large compared to field-specific effect sizes, was statistically significant and enough to make them statistically comparable to that of native speakers. These results support the need for teachers and materials developers to design pronunciation training targeted at improving second language learner interpretation of emotional prosody.