Differentiating second language vowels based on diverse phonetic input

Despite high overall proficiency in English, L1 Danish speakers often struggle to distinguish the Standard Southern British English vowel contrast /ɒ/–/ʌ/ (e.g., hot–hut), a difficulty noted for nearly a century but rarely explained empirically. This PhD thesis investigates the source of this problem using dominant models of second-language phonetic learning, arguing that these models are applicable to English in Denmark due to its cultural prominence and extensive media exposure. The thesis examines how L1 Danish speakers perceive the /ɒ/–/ʌ/ contrast and how this perception relates to Danish vowel categories. Results show that perceptual difficulty persists at levels comparable to those reported 25 years ago and that the contrast is perceived as highly similar to a Danish vowel. While some findings only partially align with model predictions, overall the results support analysing the problem within established L2 phonetic learning frameworks and outline directions for future research. [Note: This abstract does not appear in the PhD Thesis; it was composed after the fact to comply with the shorter character limit requirements of various online platforms].