This paper explores the quasinormal modes (QNMs) of a regular black hole (BH) characterized by a Minkowski core and sub-Planckian curvature. The authors focus on a specific case where the regular BH exhibits similar large-scale behavior to the Hayward BH and loop quantum gravity (LQG)-corrected BHs. A notable feature of the QNMs in this regular BH is the pronounced outburst of overtones compared to the Schwarzschild BH (SS-BH). This outburst is attributed to the deviation from the SS-BH in the near-horizon geometry due to quantum gravity effects. The paper compares the QNM properties of the regular BH with those of the Hayward BH and LQG-corrected BH, observing a similar phenomenon of overtone outburst. The authors conclude that QNMs can be a powerful tool for detecting quantum gravity effects and distinguishing different BH models. The study uses the Wentzel-Kramers-Brillouin (WKB) method and the pseudo-spectral (PS) method to determine the QNMs, with the ninth-order WKB approximation being the most accurate for this model. The results highlight the potential of QNMs in advancing our understanding of quantum gravity and BH physics.This paper explores the quasinormal modes (QNMs) of a regular black hole (BH) characterized by a Minkowski core and sub-Planckian curvature. The authors focus on a specific case where the regular BH exhibits similar large-scale behavior to the Hayward BH and loop quantum gravity (LQG)-corrected BHs. A notable feature of the QNMs in this regular BH is the pronounced outburst of overtones compared to the Schwarzschild BH (SS-BH). This outburst is attributed to the deviation from the SS-BH in the near-horizon geometry due to quantum gravity effects. The paper compares the QNM properties of the regular BH with those of the Hayward BH and LQG-corrected BH, observing a similar phenomenon of overtone outburst. The authors conclude that QNMs can be a powerful tool for detecting quantum gravity effects and distinguishing different BH models. The study uses the Wentzel-Kramers-Brillouin (WKB) method and the pseudo-spectral (PS) method to determine the QNMs, with the ninth-order WKB approximation being the most accurate for this model. The results highlight the potential of QNMs in advancing our understanding of quantum gravity and BH physics.