Purpose: Semi-occluded vocal tract (SOVT) exercises with tubes or straws have been widely used for a variety of voice disorders. Yet, the effects of longer periods of SOVT exercises (lasting for weeks) on the aging voice are not well understood. This study investigated the effects of a 6-week straw phonation in water (SPW) exercise program. Method: Thirty-seven elderly subjects with self-perceived voice problems were assigned into two groups: (a) SPW exercises with six weekly sessions and home practice (experimental group) and (b) vocal hygiene education (control group). Before and after intervention (2 weeks after the completion of the exercise program), acoustic analysis, auditory--perceptual evaluation, and self-assessment of vocal impairment were conducted. Results: Analysis of covariance revealed significant differences between the two groups in smoothed cepstral peak prominence measures, harmonics-to-noise ratio, the auditory--perceptual parameter of breathiness, and Voice Handicap Index-10 scores postintervention. No significant differences between the two groups were found for other measures. Conclusions: Our results supported the positive effects of SOVT exercises for the aging voice, with a 6-week SPW exercise program being a clinical option. Future studies should involve long-term follow-up and additional outcome measures to better understand the efficacy of SOVT exercises, particularly SPW exercises, for the aging voice.