Short Term Test-Retest Reliability of Contralateral Inhibition of Distortion Product Otoacoustic Emissions

BACKGROUND AND OBJECTIVES: Strength of medial olivocochlear reflex can be measured reliably using contralateral inhibition of distortion product otoacoustic emissions (DPOAEs) when its fine structure is considered. However, measurement of fine structure of DPOAE is difficult with clinical equipment. Thus, this study investigated the clinically relevant test-retest reliability of contralateral inhibition of DPOAEs. SUBJECTS AND METHODS: Twenty-six young adults with normal hearing sensitivity participated. DPOAEs were recorded at 27 discrete f2 frequencies between 800 Hz and 8,000 Hz at frequency resolution of 8 points per octave with and without contralateral white noise presented at 50 dB SPL. To check for short term inter-session reliability, contralateral inhibition of DPOAEs were recorded in three sessions, two recording sessions on first day separated by 30 minutes and third time after one week of the first session. Within each session, DPOAEs were recorded twice in single probe-fit condition to test for intra-session reliability. RESULTS: Cronbach’s alpha was calculated having poor reliability (α≤ 0.7) of contralateral inhibition of DPOAEs in both intra-session and inter-session conditions for most of the tested frequencies. 95% confidence intervals of contralateral inhibition magnitude also showed large variability. CONCLUSIONS: The current results showed that though DPOAE amplitudes were highly reliable across sessions, amount of inhibition of DPOAEs was not reliable when DPOAEs were measured at discrete frequencies. These findings are concurrent with the literature.

Test / Retest Reliability of DPOAE and TEOAE / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Otoacoustic emissions (OAEs) are the objective and noninvasive methods to assess cochlear function. The purpose of the present study is to determine the short-term and long-term test/retest reliability of the distortion-product otoacoustic emissions (DPOAEs) and transient-evoked otoacoustic emissions (TEOAEs). MATHODS: The short-and long-term reliability of DPOAE and TEOAE were examined in 11 normally hearing adults. DPOAE were collected in two basic forms consisting of audiograms and input/output (I/O) functions and reliabilities for TEOAE level, reproducibility index and peak stimulus level were calculated. RESULTS: The result of this study showed that the reliability of DPOAE and TEOAE was generally excellent. CONCLUSIONS: The DPOAE and TEOAE are highly reliable and useful tests to monitor the cochlear function for the purpose of study or clinical use in combination with other standard tests of audiometric function.

The Effects of Middle Ear Negative Pressure on the Transiently Evoked (TEOAEs)and Distortion Product (DPOAEs) Otoacoustic Emissions / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The clinical utility of otoacoustic emissions (OAEs) has been well established in childhood hearing screenings. As middle ear negative pressure prevails in normal children, and since all OAEs must be transmitted through the middle ear before they can be measured in the ear canal, OAEs can be affected by middle ear negative pressure. The purpose of this study is to elucidate the effect of middle ear negative pressure on the detectability of OAEs. MATERIAL AND METHODS: TEOAEs were recorded for 36 ears using click before & after tonsillectomy and, or adenoidectomy (T and, or A) operations. Before & after T and or A operations, DPOAEs were generated at six geometric mean frequencies between 1-6 kHz for two different groups, Group I (40 ears) and Group II (36 ears). Group I: 3(f2/f1) ratios (1.21, 1.22 and 1.23) were used at the fixed stimulus level (70-70 dB SPL). Group II:3 stimulus levels were used (70-70 dB SPL, 60-70 dB SPL and 30-40 dB SPL). RESULTS: The negative middle ear pressure attenuated low frequency emission more than high frequency emission. CONCLUSION: Negative middle ear pressure may increase false alarm. So pneumatic otoscopy and aural immittance testing should be utilized to predict the feasibility of applying OAEs in childhood hearing screening test.

Nonauditory Factors on Distortion Product Otoacoustic Emissions / 대한이비인후과학회지

Distortion product otoacoustic emissions(DPOAEs) have emerged as a promising clinical tool for measuring hearing status. This investigation examined the influence of four variable (test/retest reliability, test environment, gender and number of measurement points of resolution/octave) on the DPOAE response when obtained using a commercially available system, Otodynamics ILO92. Twenty normal hearing adults(10 males and 10 females) served as participants in this study. DPOAE measurements were obtained over three test sessions(baseline, 1 week retest, and a 10 minute retest following the one week measurement). Results showed that: 1) correlations were high across the three test sessions;2) test environment considerably affected the DPOAE measures below 4kHz;3) DPOAE amplitudes were significantly greater in females than males at 3 and 6kHz;and 4) DPOAE amplitudes were not affected significantly by the number of resolution points employed.