This study investigates the voiceless nasal sounds of the Ikema dialect of Miyako Ryukyuan, which is a severely endangered language spoken on the Miyako Islands in Japan. Miyako Ryukyuan exhibits a variety of geminate consonants, but Ikema is the only Miyako dialect that has developed voiceless nasal consonants as part of its word-initial geminate inventory. To investigate the voicing contrast of nasals, we explored aerodynamic and acoustic recordings from ten speakers. Acoustic measures (fundamental frequency and H1*-H2*) aimed to find voicing cues in the following vowel. Our results indicate that the airflow patterns of Ikema voiceless nasals are similar to those of Burmese, except that the voicing rate is higher in Ikema. Acoustic measures do not reveal any enhancing cue of the voicing feature. This result might be due to the longer voiced duration in the voiceless nasals, which our study also confirmed.