## 4 Discussion
### Developing an OAE Monitoring Protocol for ISSNHL
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Article** & **Conclusions** & **Support/Reject** \\ \hline [PERSON] et al. (2018) [44] & Significant changes in DPOAE SNR at 1500, 2000, and 8000 Hz; Significant associations between & \\  & SNR change and hearing threshold at 8000 and 100,000 Hz; Relationship between treatment-induced & Support \\  & change in hearing threshold and DPOAE SNR may help predict outcome at certain frequencies & \\ \hline [PERSON] \& [PERSON] & The relationship between pre-treatment presence/absence of SOAES, DPOAEs, and TEOAEs and & \\  & thresholds not significant. The study supports that OAEs can be an indicator of inner ear & Reject \\  & functional state, but they cannot be used as a prognostic test in cases of LFSNHL & \\ \hline [PERSON] \& [PERSON] (2006) & Results showed that a greater DPOAE amplitude was a significant prognostic indicator; Established & \\  & a model that revealed prognostic value of DPOAEs for ISSNHL patients; The model can be used for & Support \\  & comparison of different treatment protocols & \\ \hline [PERSON] \& [PERSON] (2010) & Results showed that a greater DPOAE amplitude was a significant prognostic indicator; Established & \\  & a model that revealed prognostic value of DPOAEs for ISSNHL patients; The model can be used for & Support \\  & comparison of different treatment protocols & \\ \hline [PERSON] (2005) [27] & Greater OAE levels following the drop in hearing thresholds were correlated with better outcome; & \\  & Monitoring TEOAEs and DPOAEs in patients with ISSNHL during/after treatment gives insight into the recovery process of OHC function parallel to subjective hearing improvement, but also & Support \\  & reveals paradoxical cases where OAEs are unexpectedly large compared with thresholds & \\ \hline [PERSON] et al. (2008) & ISSNHL patients with significant hearing improvement tended to have OAE responses; Greater & \\  & recovery was seen in the low-mid vs. high frequencies; When hearing recovery was not full, OAEs & Support \\  & did not reappear & \\ \hline [PERSON] et al. (2001) & Presence of TEOAEs in early stages of ISSNHL in those with hearing thresholds \textgreater{}40 dB HL & \\  & indicates a positive prognosis; No significant correlation between TEOAE peak amplitude and pure & Support \\  & tone improvement; TEOAEs may serve as a clinical tool for prediction of recovery in ISSNHL cases & \\ \hline [PERSON] et al. (2011) & DPOAE amplitude in patients with hearing improvement rate of 50\% was significantly larger & \\  & compared with those with hearing improvement rate of 50\% at frequencies of 3031 and 4812 Hz; & Support \\  & Significant correlation between DPOAEs before treatment and hearing recovery indicates they are a potentially useful means for predicting prognosis & Support \\ \hline [PERSON] et al. (1997) & Amplitudes of TEOAEs and DPOAEs increased concurrently with recovery of hearing threshold; & \\  & In 27\% of cases, SOAEs were detected when hearing recovered; Results suggest that the function of & \\  & OTCs deteriorated when thresholds were elevated and recovered as hearing improved to nearly & Support \\  & normal levels in ISSNHL cases with a good outcome & \\ \hline [PERSON] et al. (2011) & No significant change in DPOAEs SNR or amplitude when comparing findings before/after & Support TEOAEs; \\  & treatment for patients with significant hearing recovery; Significant and positive change in TEOAE & Support TEOAEs; \\  & SNR and reproducibility when comparing findings for patients with significant hearing recovery; & Reject DPOAEs \\  & TEOAEs are an objective, rapid, and sensitive tool in the course of ISSNHL & \\ \hline [PERSON] et al. (2010) & Function of OHCs is paired in ears with initial mid-to-moderate hearing loss and recovery is not & \\  & related to hearing improvement: Function of OHCs is impaired in ears with initial & \\  & moderately-severe to profound hearing loss and OHC improvement is important for recovery; & Support \\  & Although presence of initial DPOAE responses indicated good prognosis, absence did not always & \\  & indicate poor prognosis & \\ \hline [PERSON] et al. (2014) & Three patients with intact DPOAEs at presentation had an average improvement of 33 dB in the & \\  & PTA at 500–2000 Hz in conjunction with steroid therapy, whereas five of seven patients with absent & \\  & DPOAEs had no improvement in hearing despite therapy. The presence of DPOAEs may be a & \\  & useful prognostic indicator that positively correlates with recovery from ISSNHL & \\ \hline [PERSON] et al. (1997) & Function of OHCs is relatively spared in ears with initial mid-to-moderate hearing loss and & \\  & recovery is not related to hearing improvement: Function of OHCs is impaired in ears with initial & \\  & moderately-severe to profound hearing loss and functional improvement of OHCs is important for & \\  & recovery; Although the presence of initial DPOAE responses indicated good prognosis, absence did not always indicate poor prognosis & Support \\ \hline [PERSON] et al. (1993) & The TEOAE amplitude at initial follow-up was correlated with improvement in thresholds at the & \\  & second follow-up at 2000 Hz. Weak correlations between TEOAE amplitude at 1200 Hz and recovery & Reject \\  & of hearing. Overall, correlations were too weak to form the basis for a predictive test that could be & \\  & clinically useful; TEOAE presence is not considered a good prognostic indicator in cases of ISSNHL & \\ \hline \hline \end{tabular}
\end{table}