Purpose: The aims of this study were to explore changes in aerodynamic measures after vocal polyp removal and to determine whether the airflow regression slope (ARS) was a useful aerodynamic measurement. Methods: Thirty-nine patients (14 males and 25 females) between the ages of 19 and 76 years (median=47.62 years, SD=12.20 years) were evaluated; their details were logged in the database of Chungnam National University Hospital from March 2015 to May 2016. All patients were diagnosed with vocal polyps and underwent laryngomicrosurgery (LMS) with voice evaluation 1 week before and 1 month after LMS. Such evaluation included perceptual ratings of breathiness and strain (using the GRABS scales) and aerodynamic measurements. Aerodynamic measures included maximum phonation time (MPT), mean expiratory airflow (MEAF), mean peak air pressure (MPAP), aerodynamic resistance (ARES), aerodynamic efficiency (AEFF), and the ARS. All aerodynamic measures were compared pre- and post-LMS. Additionally, three patient subgroups (improved, worsened, and unchanged) were identified by reference to changes in the breathiness and strain ratings pre- and post-LMS. The aerodynamic measures of the three subgroups were compared. Results: All aerodynamic measures including the ARS improved significantly after LMS. The three groups did not differ significantly in any aerodynamic measure except the ARS. Conclusions: The ARS, a newly developed slope parameter, changed after LMS, and differed among the three subgroups divided by their strain ratings after LMS. Thus, the ARS identifies a strained voice.