CE-Chirp. Making ABR fast, accurate and clear! Stimulus Family

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1 Making ABR fast, accurate and clear! Response amplitudes typically 50% larger than tone burst responses, with the potential to halve the test time CE-Chirp Stimulus Family The Gold standard for threshold assessment p Stimulus Family Our work has shown that narrowband CE-Chirps offer frequencyspecific testing in typically half the time taken by tone pips. Given that a sleeping baby is a ticking time bomb waiting to go off, that s an advantage you can t afford to pass up. It s frustrating that not all ABR systems offer this stimulus.* Guy Lightfoot PhD 2013

2 The Challenge: Identifying wave V close to threshold Difficult and time consuming testing Correctly diagnosing the type and degree of hearing loss so that rehabilitation can occur, is one of the most important roles of an audiologist or physician. The CE-Chirp stimulus family Traditional CE-Chirp & NB CE-Chirp from 2007 & current CE-Chirp LS Family NB CE-Chirp LS family (2014) All with normative data included Click and tone burst ABR have been successfully used for many years, but despite their common clinical use these stimuli are associated with long test times and small wave V amplitudes. This results in ABR traces which are difficult to interpret, leading clinicians to have less confidence in what they see on screen. The solution Large ABR waveforms are dependent on synchronous neural firing. Unfortunately, click and tone burst stimuli are not designed to stimulate the cochlea optimally. As the cochlea is tonotopically organised, the different frequency components of the click and tone bursts reach their point of stimulation on the basilar membranes at different times. This leads to temporal smearing of the ABR result shown on screen. The solution to this problem is to design a stimulus which stimulates all the desired frequencies of the basilar membrane at the same time. A preview of the benefits of the CE-Chirp stimulus family Response amplitudes typically 50% larger than tone burst responses, with the potential to halve the test time Easier interpretation Reduced test time Increased confidence 2

3 The Solution: CE-Chirp stimulus family Compensating for the cochlear delay The CE-Chirp stimulus family was developed following many years of extensive human studies by numerous researchers including Claus Elberling, the researcher who the CE-Chirp has been named in honor of. These studies determined the delay model that had the best match for the average human cochlea; the outcome being the innovative CE-Chirp. For the clinician this means larger amplitude waveform responses allowing for easier threshold identification 1. In 2007, Interacoustics was the first company to introduce the revolutionary CE-Chirp into a diagnostic evoked potentials platform leading to markedly reduced test time and easier interpretation for the clinician. Response amplitudes up to twice the size when compared with traditional clicks or tone bursts can be achieved with both the broadband CE- Chirp and frequency specific narrow band CE-Chirps. The CE-Chirp LS stimulus family is an overall improvement to the original CE-Chirp stimulus family. For an easier visual evaluation of the Narrow Band (NB) CE-Chirp responses, each of the NB CE-Chirp stimuli have been time-shifted to provide latencies similar to the Click and the CE-Chirp LS stimulus. The time-shifted NB CE-Chirp are named NB CE-Chirp LS, as the placements are level specific. The similarities between the CE-Chirp LS and the Click lie in the spectrum and calibration of the stimuli, while the difference lies in the presentation timing of the low, mid and high frequency components of the stimulus in order to provide greater neural synchronization. Click stimulus CE-Chirp LS stimulus 1 Elberling, C., & Don, M. (2008). Auditory brainstem responses to a chirp stimulus designed from derived-band latencies in normal-hearing subjects. J Acoust Soc Am, 124, Click versus CE-Chirp Stimulus Click Threshold CE-Chirp LS Threshold While the original broadband CE-Chirp was designed for optimal response amplitudes at medium stimulation intensities, the level specific (LS) broadband CE-Chirp provides clearer waveform morphology at high and low intensities. Comparison of click and broadband CE-Chirp LS stimulus amplitudes and latencies. The wave V amplitudes are larger with the broadband CE-Chirp LS. 3

4 The Proof: Is in the waveforms CE-Chirp Stimulus Family The Gold standard for threshold assessment Learn more about the clinical advantages of the CE-Chirp family at UK NHSP approved* ABR threshold with NB CE-Chirps NB CE-Chirps ABR is a fast, accurate tool for estimating the hearing threshold. These results are essential for the diagnostic evaluation. *certified for use in the UK newborn hearing screening programme. Comparison of ABR response amplitude, test time, and estimation of hearing threshold using frequency specific chirp and tone pip stimuli in newborns. (Ferm, Lightfoot & Stevens, 2013) Results & Conclusion: Overall, NB CE-Chirp responses were 64% larger than the tone pip responses. Fmp was significantly higher for NB CE-Chirps. It is anticipated that there could be significant reductions in test time for the same signal to noise ratio by using NB CE- Chirps when testing newborns. *tone bursts are also referred to as tone pips. 4

5 Tone burst versus NB-CE-Chirp stimulus The waveforms are for 4 different babies all 8 weeks corrected age. Courtesy of Inga Ferm. 500Hz Tone Burst vs 500Hz NB CE-Chirp 1kHz Tone Burst vs 1kHz NB CE-Chirp 100nv/div 100nv/div Average responses for 4 frequencies were 50% larger Comparison of 500Hz tone burst and 500Hz NB CE-Chirp responses. dbnhl 2kHz Tone Burst vs 2kHz NB CE-Chirp 100nv/div 15 Comparison of 1kHz tone burst and 1kHz NB CE-Chirp responses. dbnhl 4kHz Tone Burst vs 4kHz NB CE-Chirp 100nv/div Larger response amplitudes. Reduces test time Comparison of 2kHz tone burst and 2kHz NB CE-Chirp 10 responses. Comparison of 4kHz tone burst and 4kHz NB CE-Chirp 20 responses. dbnhl dbnhl Further comparisons of ABR response amplitudes, test time, and estimation of hearing threshold using frequency-specific chirp and tone pip stimuli in newborns: Findings at 0.5 and 2 khz. (Ferm & Lightfoot, 2015) Conclusion: The advantages of NB CE-Chirps over tone pips* we previously identified at 4 and 1 khz extends to 0.5 and 2 khz, which supports the use of NB CE-Chirps when testing newborns. We propose that ABR nhl threshold to ehl corrections for NB CE-Chirps should be approximately 5 db less than corrections for tone pips at 0.5 and 2 khz, mirroring our recommendation at 4 and 1 khz. Guidelines for the early audiological assessment and management of babies referred from the Newborn Hearing Screening Program. (Stevens, Sutton & Wood (eds), 2013) Narrow band chirps are now acceptable as an alternative to tone pips for ABR testing, with nhl to ehl correction values being provided. The two advantages of using chirps are: The ABR response is usually larger which should reduce test time (Ferm et al., 2013; Elberling & Don, 2010). The confidence intervals for the ehl threshold value are smaller. Comparing auditory brainstem responses (ABRs) to toneburst and narrow band CE-chirp in young infants. (Rodrigues, Ramos & Lewis, 2013) Conclusion: Narrow band CE-chirp ABRs generate shorter latencies than the toneburst ABRs, especially to low frequencies. Higher amplitudes were found with narrow band CE-chirp stimuli for all frequencies tested, except to high levels. 5

6 NB CE-Chirps ASSR threshold The NB CE-Chirp ASSR was developed by Cebulla, Stürzebecher and Elberling (2006) and has demonstrated up to 50% faster detection and even more accurate hearing thresholds compared to earlier generation ASSR systems. Furthermore, the results of NB CE-Chirp ASSR are optimized for hearing aid fitting. The following articles highlight the benefits and usability of the CE-Chirp stimulus family in clinical testing. Average test time 18 minutes Refining the audiological assessment in children using narrow-band CE-Chirp - evoked auditory steady state responses (Venail et al., 2014) Narrow-band CE-Chirps allow a fast and reliable assessment of auditory thresholds in children, especially in the low-frequency range, by comparison with other stimuli. Fast Hearing-Threshold Estimation Using Multiple Auditory Steady-State Responses with Narrow-Band Chirps and Adaptive Stimulus Patterns (Mühler, Mentzel & Verhey, 2012) The average differences between the behavioural hearing thresholds and the ASSR threshold estimate were 10, 8, 13, and 15 db for test frequencies of 500, 1000, 2000, and 4000 Hz, respectively. The average overall test duration of 18.6 minutes for the threshold estimations at the four frequencies and both ears demonstrates the benefit of an adaptive recording algorithm and the efficiency of optimized narrow-band chirp stimuli. Establishing auditory steadystate response thresholds to narrow band CE-chirps in full-term neonates (Rodrigues, G. R., & Lewis, D. R., 2014) 21 minutes average test time In this study ASSR thresholds estimated from 90% of the neonates were 34.5, 28, 12.5 and 15 db nhl. It required 21,2 (±5) min on average to obtain thresholds in each ear and ASSR thresholds to narrow band CE-chirp in neonates are not significant for adult ASSR thresholds, except at 500 Hz, when the ASSR thresholds in neonates tend to be greater than in adults. 6 Auditory Steady-State Evoked Responses for Preterm and Term Neonates (Ribeiro, Carvallo & Marcoux, 2010) Significant threshold differences were measured between the groups at 500 and 4000 Hz, while the thresholds at 1000 and 2000 Hz were similar. These results indicate that ASSRs can be effectively measured with a similar signal-to-noise ratio in both groups, but that there is a significant maturational effect occurring during gestation at the level of structures, which participates in the formation of the ASSR at 500 and 4000 Hz. Threshold prediction in children with sensorioneural hearing loss using the auditory steady-state responses and tone-evoked auditory brain stem response (Rodrigues & Lewis, 2010) Multiple ASSRs have strong correlations to tone-evoked ABR and to behavioral thresholds obtained during follow-up in hearing impaired infants and young children. These results might be useful in order to provide further evidence for the use of multiple ASSRs, as an alternative tool to tone-evoked ABR, although further data are still required.

7 References & Suggested Reading Learn more about the CE- Chirp stimulus family at eclipse Articles Cebulla, M., Stürzebecher, E., & Elberling, C. (2006). Objective detection of auditory steadystate responses: Comparison of onesample and q-sample tests. J Am Acad Audiol, 17(2), Elberling, C., Don, M., Cebulla, M., & Stürzebecher, E. (2007). Auditory steady-state responses to chirp stimuli based on cochlear traveling wave delay. J Acoust Soc Am, 122(5), Ribeiro, F. M., Chapchap, M. J., & Leite, R. A. (2011). Chirp-ASSR thresholds for normal hearing term and preterm neonates. Presented at the International Evoked Response Audiometry Study Group (IERASG) Conference, Moscow, Russia. Rodrigues, G. R., & Lewis, D. (2010). Threshold prediction in children with sensorioneural hearing loss using the auditory steady-state responses and tone-evoked auditory brain stem response. Int J Pediatric Otorhinolaryngol, 74(5), Stimulus Family Our work has shown that narrowband CE-Chirps offer frequencyspecific testing in typically half the time taken by tone pips. Given that a sleeping baby is a ticking time bomb waiting to go off, that s an advantage you can t afford to pass up. It s frustrating that not all ABR systems offer this stimulus.* Guy Lightfoot PhD 2013 Ferm, I., & Lightfoot, G. J. (2015). Further comparisons of ABR response amplitudes, test time, and estimation of hearing threshold using frequencyspecific chirp and tone pip stimuli in newborns: Findings at 0.5 and 2 khz. Int J Audiol, 54(10), Ferm, I., Lightfoot, G., & Stevens, J. (2013). Comparison of ABR response amplitude, test time, and estimation of hearing threshold using frequency specific chirp and tone pip stimuli in newborns. Int J Audiol, 52(6), Kristensen, S.G., & Elberling, C. (2012). Auditory brainstem responses to levelspecific chirps in normal-hearing adults. J Am Acad Audiol, 23(9), Mühler, R., Mentzel, K., & Verhey, J. (2012). Fast hearing-threshold estimation using multiple auditory steady-state responses with narrow-band chirps and adaptive stimulus patterns. The Scientific World Journal, 2012: Ribeiro, F. M., Carvallo, R. M., & Marcoux, A. M. (2010). Auditory steady-state evoked responses for preterm and term neonates. Audiol Neurootol, 15(2), Rodrigues, G. R., Ramos, N., & Lewis, D. R. (2013). Comparing auditory brainstem responses (ABRs) to toneburst and narrow band CE- Chirp in young infants. Int J Pediatr Otorhinolaryngol, 77(9), Rodrigues, G. R., & Lewis, D. (2014) Establishing auditory steady-state response thresholds to narrow band CEchirps in full-term neonates. Int J Pediatr Otorhinolaryngol, 78(2), Stevens, J. Sutton & G. Wood, S (Eds) (2013). Guidelines for the early audiological assessment and management of babies referred from the Newborn Hearing Screening Programme, V3.1 NeonateAssess_2014.pdf Sutton, G. and Lightfoot, G. (Eds) 2013 Guidance for Auditory Brainstem Response testing in Babies, V ABRneonate_2014.pdf Venail, F., Artaud, J. P., Blanchet, C., Uziel, A., & Mondain, M. (2015). Refining the audiological assessment in children using narrow-band CE-Chirpevoked auditory steady state responses. Intl J Audiol, 54(2),

8 Where is the CE-Chirp stimulus family available? Todd B. Sauter, M.A. Audiology Associates of Worcester Massachusetts Database NOAH OtoAccess TM The Eclipse has the largest number of clinically-relevant features of any AEP device today. The platform is an excellent OAE DPOAE Data Storage & Sharing Data Storage & Sharing ABR EP25 * blend of parameter flexibility and user-friendliness. Screening and clinical DPOAE ABR, MLR, LLR, P300, MMN, ECochG, eabr TEOAE EP15 * Screening and clinical TEOAE ABR Balance VEMP cvemp ovemp The Eclipse *The CE-Chirp stimulus family is included in the EP25 and ASSR and is optional for the EP15 software for the Eclipse. ABRIS Automated ABR screening ASSR * Threshold assessment Database NOAH OtoAccess TM Interacoustics A/S OAE Data Storage & Sharing Data Storage & Sharing ABR Audiometer Allé Middelfart Denmark T F info@interacoustics.com interacoustics.com DPOAE440 Screening and clinical DPOAE TEOAE440 Screening and clinical TEOAE The Titan ABRIS440 Automated ABR infant screening Impedance IMP440 * Screening, diagnostic & clinical impedance *The original CE-Chirp and the special HiLo CE-Chirp are included in the ABRIS440 automated ABR software for the Titan. ABR/OAE Balance Assessment Fitting Systems Middle Ear Analyzers Audiometers Interacoustics a/s /2018