A single session of vocalizing through a straw (straw phonation) has been associated with consistent or increased acoustic output and chorister-reported improved choral sound and vocal efficiency. Some choristers, however, report discomfort from the intense pressure of vocalizing through a stirring straw (2.5-3.0 mm opening). It is unclear whether participants acclimate to this pressure over time. Two mixed and two treble choirs sang a unison melody, participated in a straw protocol, and sang the melody again. Choristers used the protocol during warmups in four subsequent rehearsals and repeated the same pretest-posttest protocols on the final day. Survey results indicated (a) at least 89.7% of participants self-reported improved choral sound and more efficient/comfortable individual voicing after the protocols on both data collection days, and (b) participants reported greater impact on their warmup on the final day. Analyses revealed (a) choirs sang with 1.35 to 3.37 dB SPL greater mean spectral energy after the protocols on the first day and 1.63 to 2.65 dB SPL on the final day, and (b) one choir evidenced less change on the final day, one evidenced more change, and two evidenced no statistical difference. These results may represent a modest acclimation effect for choristers using straw phonation.