ObjectivesThe acoustic voice quality index (AVQI) is a reliable tool that objectively assesses dysphonia levels using six acoustic parameters. Despite its high criterionârelated concurrent validity, diagnostic accuracy, and minimal detectable change derived from testâretest reliability, the minimal important difference (MID) of the AVQI has not been tested before. This study aimed to estimate the MIDs of AVQI for improvement audibly perceived by clinicians and selfâreported improvement by patients.MethodsA retrospective study was conducted on 110 patients who received treatment for voice disorders. Patients completed AVQI and Voice Handicap Indexâ10 (VHIâ10) questionnaires before and after the therapy. The MIDs of the AVQI were estimated using the anchor of either auditoryâperceptual judgment of total dysphonia levels by clinicians or the VHIâ10 questionnaire by patients. A distributionâbased approach was also used to complement the results.ResultsFirst, using the auditoryâperceptual anchor, a decrease of 0.95 in the AVQI was estimated as the MID for clinicians' perception, as a result of the receiver operating curve. Then, using the patientâreported anchor, an improvement of 1.36 in the AVQI was estimated as the MID for patients' voiceârelated disability. The distributionâbased approach also ensured the anchorâbased results of both the MIDs.ConclusionsThe AVQI is a reliable and valid tool for evaluating voice quality, and a 0.95 decrease in the AVQI represents a meaningful improvement for clinicians' perception, whereas a 1.36 decrease in the AVQI influences patients' selfâreported disability. This study contributes to understanding the minimal change necessary for clinicians to make informed decisions and ensure patient satisfaction.Level of Evidence3 Laryngoscope, 2023