This study aimed to investigate the impact of various sentence memorization methods on the improvement of English proficiency in second language (L2) learners. 24 students participated in the study, and over the course of 4 weeks, scores for comparative analysis were obtained using various methods such as silent reading, sentence writing, memorization through personal speech, and recording and listening to one’s own voice. Different content was used for each topic, and the 24 students alternated between memorization methods each week, experimenting with all the techniques provided. Memorization through personal speaking was found to be the most effective method. Next, writing sentences, listening to recordings of one’s own voice, and silent reading were ranked in order of effectiveness. Interestingly, the reason why the score for the self-speech method was lower despite using the same voice proves that the higher the frequency of the voice, the more helpful it is in memorization. Conversely, the low-frequency nature of recorded speech resulted in reduced learning effectiveness due to reliance on auditory filtering. This study highlights the importance of choosing an appropriate memorization method for learners who want better results in foreign language learning.