Objective To investigate the relationship between the narrow band Chirp auditory brainstem response (NB Chirp ABR) response thresholds, 40 Hz auditory event related potential (40 Hz AERP) response thresholds and pure-tone audiometry (PTA) thresholds in normal hearing adults under sound stimulation of different frequencies. Methods A total of 100 ears of 50 normal-hearing adult subjects were selected as the experimental group. PTA, NB Chirp ABR and 40 Hz AERP tests were conducted at the frequencies of 0.5, 1, 2, and 4 kHz. The relationship between the NB Chirp ABR, 40 Hz AERP response thresholds and the PTA thresholds were analyzed using paired samples t-tests, Pearson correlation coefficients, and scatter plots. The mean differences between the response thresholds and the PTA thresholds at each frequency were calculated as the calibration values for our laboratory. Additionally, 22 ears of 11 normal-hearing adult subjects were selected as the validation group to evaluate the accuracy of predicting behavioral hearing thresholds using NB Chirp ABR, 40 Hz AERP, and their combined application, respectively. Mean absolute error (MAE), mean square error (MSE), root mean square error (RMSE), and correlation coefficients were used as evaluation metrics. Results At the frequencies of 0.5, 1, 2, and 4 kHz, the correlation coefficients between the NB Chirp ABR response threshold and the PTA threshold were 0.601, 0.672, 0.805, 0.931, and the correlation coefficients between the 40 Hz AERP response threshold and the PTA threshold were 0.763, 0.737, 0.643, 0.580, respectively. The combined application of NB Chirp ABR and 40 Hz AERP, using laboratory calibration values established in this study, demonstrated the accuracy of predicting behavioral hearing thresholds with MAE, MSE, RMSE, and the correlation coefficient values of 2.216 dB nHL, 7.509 dB nHL, 2.740 dB nHL and 0.906, respectively. Conclusion NB Chirp ABR has application value in the assessment of hearing function. When combined with 40 Hz AERP, with 40 Hz AERP used at 0.5 and 1 kHz, and NB Chirp ABR used at 2 and 4 kHz, it can improve the accuracy of auditory function assessment.