The aerodynamic puzzle of nasalized fricatives: Aerodynamic and perceptual evidence from Scottish Gaelic

Scottish Gaelic is sometimes described as having nasalized fricatives (vertical bar(v) over tilde vertical bar/distinctively, and [(f) over tilde, (x) over tilde, (h) over tilde], etc. through assimilation). However, there are claims that it is not aerodynamically possible to open the velum for nasalization while maintaining frication noise. We present aerodynamic data from 14 native Scottish Gaelic speakers to determine how the posited nasalized fricatives in this language are realized. Most tokens demonstrate loss of nasalization, but nasalization does occur in some contexts without aerodynamic conflict, e.g., nasalization with the consonant realized as an approximant, nasalization of [(h) over tilde], nasalization on the preceding vowel, or sequential frication and nasalization. Furthermore, a very few tokens do contain simultaneous nasalization and frication with a tradeoff in airflow. We also present perceptual evidence showing that Gaelic listeners can hear this distinction slightly better than chance. Thus, instrumental data from one of the few languages in the world described as having nasalized fricatives confirms that the claimed sounds are not made by producing strong nasalization concurrently with clear frication noise. Furthermore, although speakers most often neutralize the nasalization, when they maintain it, they do so through a variety of phonetic mechanisms, even within a single language.