Introduction and objective: Hearing improvement assessment in patients with Idiopathic Sudden Sensorineural Hearing Loss (ISSNHL) is complex. Methods used to evaluate the effectiveness of ISSNHL therapy do not include variety of PTA (Pure Tone Audiometry) curves. The aim of this paper is to assess usefulness of Multi-Frequency Hearing Improvement Analysis (MHIA) as an alternative method employed to evaluate the effectiveness of the ISSNHL treatment. Material and methods: Medical records of 218 patients with ISSNHL were statistically analysed in a retrospective study with regard to PTA results. Achieved results were compared using the following methods: Siegel’s criteria, Wilson’s criteria, and MHIA. Results: The analysis based on Siegel’s criteria, which concerned the effectiveness of therapy, was as follows: complete recovery: 94 (43,1%), partial recovery: 20 (9,2%), slight recovery: 17 (7,8%), no recovery: 87 (39,9%). The MHIA analysis revealed the following weighted arithmetic mean recovery rate: Air Conduction and Bone Conduction respectively – complete recovery (23,5%; 43,14%), partial recovery: (9,12%; 20,51%); slight recovery (6,65%; 7,4%), no recovery (68,36%; 54,98%). Conclusions: MHIA corrects the overestimation of complete recovery rate based on Siegel’s criteria. Using mean auditory threshold stimulus as a baseline to evaluate hearing improvement in studies could distort the interpretation of research findings. Clinical features and usability of MHIA in diverse groups of patients require further studies.