The ABR (auditory brain stem response) is neural response to a certain stimulus, which is useful in evaluation of the hearing integrity in normal and hearing loss. Clinically ABR is applied in indirect estimation of hearing thresholds in adults and infants(Hecox et al., 1974) and in detection pathologies of peripheral and central nerve systems(Starr et al., 1975). A various kind of stimulus could be used to acquire ABRs. Among them click and the tone burst are the most frequently used stimulus in current clinical environments. Tone bursts are used in some circumstances due to their benefits regarding frequency specific threshold, however practically speaking its amplitudes are relatively small and need longer test time and experienced examiner is required for the tone burst ABRs. On the other hand, clicks are used relatively more often to obtain screening ABRs. Since they have of rapid onset and broad-frequency spectrum, clicks elicit larger waveform amplitude and higher neural synchrony(Don et al., 1994; Gorga et al., 2006). Though its usefulness and wide adaptation throughout the world wide clinics and hearing loss screening, there seems to be some pitfalls of click evoked ABRs. In the past, since it is produced in a wide range of frequency, it was expected to stimulate more fibers(Debruyne, 1986) to reflect all the behavioral thresholds. Despite this expectation, according to the previous studies, the strongest correlation between click ABR and pure-tone thresholds were found at 2 and 4 kHz which represents the only basal portion of the cochlea(Dau et al., 2000; Don et al., 1978). This is thought to be due to cochlear traveling way delay, which could lead to natural phase cancelations among the collective responses from individual neural unit which contributes to the ABR response(Don et al., 2005; Maloff et al., 2014). In addition, with click evoked ABRs, cochlear tonotopic region below the frequency of 1000 Hz might not be excited especially in low stimulus, near the threshold level because the waveform is likely to represent neural activity closer to 1000~4000 Hz region(Maloff et al., 2014). Reflecting these recent changes, ABRs with combination of narrow band stimulus and click is recommended by some authors not to rule out low frequency hearing losses(Gorga et al., 2006). Furthermore “The Current Joint Committee on Infant Hearing (JCIH)” also suggested including the tone burst, which is narrow band stimuli, for screening hearing loss infants(Fobel et al., 2004). As the modality to enhance the synchrony and compensate the traveling wave delay, the chirp is designed. For the chirp stimulus, higher frequency components delayed relative to lower frequency components(Dau et al., 2000). This concept was applied to auditory electrophysiology at 1982(Harrison et al., 1982) and it is intensively studied in various kinds of auditory fields(Elberling et al., 2007). Several chirp designs have been proposed and tested over the decade. For example, Fobel and Dau reported comparison results about the O-chirp which was based on stimulus frequency otoacoustic emissions, A-chirp which was based on tone burst ABR latencies, and M-chirp which has temporal envelope starting with very small amplitudes at the low frequencies and increasing nonlinearly. Among these different chirps A-chirp was reported to have most robust amplitudes(Fobel et al., 2004). Recently a new chirp, CE-Chirp has been introduced and its result has been reported in several studies that evaluated responses from normal hearing subjects(Elberling et al., 2008; Elberling et al., 2010b; Gotsche-Rasmussen et al., 2012). The design of this chirp was based on derived band ABR latency information from normal hearing adults. One of the unique and unwanted findings in the CE-Chirp ABRs is low amplitude at high intensity level stimulus and this was also found in our study report at the IERASG 2011(Cho et al., 2011). The main reason for this drawback of the CE-Chirp is presumed to be from the upward spread of excitation and changes in cochlea-neural delay according to its stimulus levels(Elberling et al., 2010a). In LS-Chirp, which is variation from the CE-Chirp, level dependent stimuli (for example: shorter duration and longer latency for high intensity level) is equipped to compensated previous pitfalls and now this stimulus is getting ready for the clinical release. Therefore, according to the recent paradigm, we believe that LS-Chirp is the most up-to-date form among the chirp stimulus families. Regarding this LS-Chirp, authors have analyzed some unpublished preliminary data. We compared wave amplitudes and ABR thresholds from Click and LS-Chirp stimulus in normal hearing (n=7), and found out that LS-Chirp had statistically better performance in both two parameters (larger amplitudes, lower threshold difference from behavioral threshold). Also, especially in the high intensity level (70 dBnHL) LS-chirp revealed statistically higher amplitude than click evoked ABRs. There are many reports regarding the ABRs from chirp in normal hearing subjects, however reports from data acquired from hearing loss subjects are rare. Recently, Erin and Hood reported considerably stable threshold correlation to behavioral threshold using M-chirp ABRs in hearing loss subjects, and they also found that Chirp ABRs were favorable than click ABRs as for some aspect not only in normal hearing but also in hearing loss subjects(Maloff et al., 2014). We will report here in sensorineural hearing loss patients using LS-chirp. In conclusion, though click is the conventional widely applied stimulus for ABRs, a chirp stimulus was able to generates larger neural amplitude with suitable models of cochlear traveling wave delay than conventional responses (Konrad-Martin et al., 2012; Kristensen et al., 2012; Maloff et al., 2014). And it is possible that this new stimulus could be adjuvant modality to retrieve more information about the subjects hearing objectively. However further study regarding chirp ABRs is necessary for this new stimulus to replace the click ABRs, because it is not clearly understood and interpreted in certain circumstances, especially in pathologic condition (sensorineural hearing loss and central auditory pathway lesions). Reference Cho, S.W., Han, K.H., Shin, S.O., Lee, J.H. 2011. Comparison between CE-Chrip and Click evoked ABR in normal and sensorineural hearing loss. poster presentation at XXII IERASG BIENNIAL SYMPOSIUM, 2011. Dau, T., Wegner, O., Mellert, V., Kollmeier, B. 2000. 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