Clinical Otolaryngology & Allied SciencesVolume 24, Issue 4 p. 377-383 Oto Acoustic Emissions (OAE): the shape-similarity of pure-tone audiogram and OAE-gram G. A. Van Zanten, G. A. Van Zanten (Rotterdam, the Netherlands)Search for more papers by this authorA. Van De Sande, A. Van De Sande (Rotterdam, the Netherlands)Search for more papers by this authorM. P. Brocaar, M. P. Brocaar (Rotterdam, the Netherlands)Search for more papers by this author G. A. Van Zanten, G. A. Van Zanten (Rotterdam, the Netherlands)Search for more papers by this authorA. Van De Sande, A. Van De Sande (Rotterdam, the Netherlands)Search for more papers by this authorM. P. Brocaar, M. P. Brocaar (Rotterdam, the Netherlands)Search for more papers by this author First published: 25 December 2001 https://doi.org/10.1046/j.1365-2273.1999.00280-22.xRead the full textAbout ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume24, Issue4August 1999Pages 377-383 RelatedInformation

Click-evoked otoacoustic emissions (cEOAEs) were repeatedly recorded in an operational sample of 144 very low birth weight (VLBW) infants. A subgroup of 22 was composed of all those babies in which at least 4 recordings were successfully done. The mean birth weight of this group was 1040 g, and the mean duration of assisted ventilation was 17 days. The OAE-recordings were done in the post conceptional age (PCA) range between 30 and 68 weeks. In relation to ear function screening it was shown that the EOAE was present in 95% of the ears at least once at any age, while it was present in all recordings in only 34%. From a longitudinal analysis of the recordings per infant it appeared that: (1) the OAE recorded was already present in one infant at the PCA of 29.4 weeks; (2) in most infants the level of the OAE varies strongly between recordings; (3) in each infant the OAE-level shows an increase with age, on average this growth amounts to 10 dB between the PC As of 31 and 42 weeks; (4) there is no clearcut difference in the growth of high- and low-frequency components of the EOAE.

For the purposes of studying the phenomenon of evoked oto-acoustic emissions (EOAEs) in very-low-birth-weight (VLBW) infants, and the conditions affecting the utility of EOAE ear screening in this population, click EOAEs were repeatedly recorded in ears of 144 VLBW infants, at different postconceptional ages of the infants and at two different test sites, i.e. in the neonatal high-care unit (ward), or at the neonatal outpatient clinic. The postconceptional age of the infants examined in the ward was 30-49 weeks and 37-66 weeks for the infants examined at the outpatient clinic. Overall 840 recording attempts were done. In the ward 86% of these attempts (388) were successful against 60% (of 452 attempts) at the outpatient clinic. In the latter group of infants the success rate of recording was only 33% at the corrected age of 6 months, which is significantly less than the 66% until the corrected age of 3 months. For a cross-sectional analysis of age effects one ear of each successfully recorded infant was selected. Analysis of the 127 successful recordings revealed that the EOAE prevalence was 71% in the ward (54% for infants receiving extra oxygen per naso) and 91% at the outpatient clinic. Compared with healthy newborns, VLBW infants are much more difficult to test, especially at the outpatient clinic. However, the EOAE prevalence at this test site is the highest and approaches that in healthy newborns. At the outpatient clinic response levels of EOAEs recorded approach levels found in healthy newborns. The higher success rate of recording in the ward and the lower EOAE prevalence are two counteracting factors as to the utility of EOAE-based ear screening of VLBW infants.

We tend not to think of music as noise but as a pleasant sound. Yet, played loud enough, music can become a threat to the human ear. The question arises whether professional musicians suffer from hearing losses caused by their playing of music. The hearing of students at the Rotterdam conservatory was studied; medical students served as a reference group. High percentages of audiometric noise dips (16%) and high-frequency losses (20%) were found in students of the conservatory, as well as a high percentage (72%) of extended high-frequency losses relative to the reference curves of Dreschler et al. Surprisingly, an equally large (and in the high-frequency region an even higher) percentage of hearing losses was found in the control group of medical students with the same median age. In sum, the exposure of conservatory students to the practice of music has as yet had no effect on their hearing.

In a prospective study the effects on the voice of nandrolone decanoate super-imposed on cyclical hormonal replacement therapy (HRT) given to post-menopausal women suffering from a severe form osteoporosis were compared with the effects of HRT alone. Comparing the experimental group with the control group, after one year of medication in the experimental group a higher percentage of patients had: a lower fundamental frequency during speech, a loss of high frequencies and an increase in voice instability and creakiness. The lowering of the frequencies and the increase of instability can be explained by histological changes in the vocal cords and by problems in the adaptation to these histological changes.

The aim of this study was to assess the conductive loss component (CLC) by brainstem electric response audiometry. A bone-conducted noise was used to mask out the response to a conventional air-conducted click stimulus. The difference between the levels of the click and the noise is defined as the masked threshold to noise ratio (MTNR). This MTNR was determined for 21 normal ears (MTNR = -13 +/- 5 dB). The increase in MTNR compared to this normative value is a measure of the CLC. For 10 ears with an artificially induced purely conductive loss, the increase in MTNR is in good agreement with the results of conventional pure-tone and brainstem electric response audiometry.

The frequency specificity of the ABR threshold evoked by a 1000-Hz filtered click was determined in subjects with sloping cochlear hearing losses, both high- and low-frequency in character. The results show that the ABR threshold evoked by this stimulus is low-frequency specific. The standard error in estimating the 1000-Hz pure-tone threshold (PTT) is 10.4 dB, which equals that for estimating the 3000-Hz PTT from the routinely used click-evoked ABR threshold. The ABR threshold evoked by a 1000-Hz filtered click can therefore be regarded as an accurate tool to predict the pure-tone hearing loss at 1000-Hz. In comparison with the ABR threshold evoked by a click masked with 1590-Hz high-pass noise, the ABR threshold evoked by a 1000-Hz filtered click has a larger dynamic range, yields a larger number of useful responses and is less time consuming. For clinical low-frequency-specific ABR threshold assessment, the 1000-Hz filtered click is therefore preeminently useful.

Spontaneous otoacoustic emissions (SOAEs) are pure-tone like signals, spontaneously present in the ear canal. In normal adult ears the prevalence of SOAEs is reported to be 30-70%, probably depending on the noise floor of the recordings. In infant studies, results on the SOAE prevalence are rare. SOAEs as well as evoked otoacoustic emissions (EOAEs) were recorded in healthy newborns. Their ages varied between 1 and 10 days. The recordings were done with commercially available equipment in a separate not sound treated room of the obstetric department. The prevalence of SOAEs was 78%, which is higher than previously reported for adults as well as healthy newborns. The prevalence was not significantly different between left and right ears, or genders. The number of emissions per emitting ear amounted on average 5.5. The median number of SOAEs in boys (3.3) is significantly lower than in girls (4.6). The SOAE levels were between -2 and 42 dB SPL. The mean level per emitting ear was 8.0 dB SPL and not significantly different between right and left ears or genders. However, the level of the strongest emission per emitting ear was significantly higher for right than for left ears. In contrast with adults most of the emissions (70%) are at frequencies above 2 kHz. Comparing the levels of the EOAEs between ears with and without SOAEs we found a statistically significant higher EOAE level in ears with SOAEs. This supports our previous hypothesis that the higher EOAE level found in healthy newborns is partly due to the more frequent presence of stronger SOAEs in healthy newborns.(ABSTRACT TRUNCATED AT 250 WORDS)

Click-evoked oto-acoustic emissions (EOAEs) were recorded in 1036 ears of healthy newborns and in 71 normal-hearing adult ears. Newborns aged between 3 and 238 h were examined in a separate but not silent room of the obstetric ward. The adults were tested in a quiet but not sound-treated room. The recordings were more difficult in the newborn than in the adult, which was mirrored in recording parameters such as the time required for measurement (up to 7 min in newborns vs. 1-2 min in adult ears). Recording was always successful in adults, while retests were necessary in 4% of newborns. Also the artefact-rejection level and the stimulus stability were more favourable in adults. Still, EOAE recording for screening purposes in newborns seems feasible. Response levels in newborns (range 1.6-38.6; mean 20.2 dB SPL) appear to be higher than in adults (range 2.7-20.6; mean 12.8 dB SPL). The overall prevalence of EOAEs in newborns amounted to 93.4% and appeared to be age related. It rises from 78% in ears from newborns younger than 36 h to 99% in ears of newborns older than 108 h. This rise may be related to the middle ear clearance of amniotic fluid in the first days post partum. The prevalence in newborns older than 3-4 days is comparable with the prevalence of 97.2% in adults. Therefore, newborns should not be screened before the age of 4 days. In search of an objective EOAE detection variable, the prevalence of EOAEs for different age groups was calculated for various criterion values of reproducibility. These prevalences were compared to subjectively scored EOAE prevalences in the same age groups. A reproducibility criterion of about 50% appears to be useful for mass screening in newborns.

In this study, the frequency specificity of the ABR threshold to stimulation with a click masked with 1590-Hz high-pass noise was determined in subjects with sloping cochlear hearing losses both high- and low-frequency in character. The results show that the ABR threshold elicited by this stimulus is low-frequency specific. The standard error in estimating the 1000-Hz pure-tone threshold from the high-pass-noise-masked click-evoked ABR threshold is 10.2 dB which equals that for estimating the 3000-Hz pure-tone threshold from the routinely used unmasked click ABR threshold. The ABR threshold elicited by a click masked with 1590-Hz high-pass noise can therefore be regarded as an accurate tool to predict the pure-tone hearing loss at 1000 Hz. However, this method is less suitable for routine clinical testing because of the masking noise needed: the occasional high loudness level adversely affects the response quality and reduces the dynamic range of pure-tone hearing losses to be assessed. A third disadvantage is that determining the masking level electrophysiologically for each ear is time consuming. The search for a method with no or less masking noise should therefore continue.

Evoked otoacoustic emissions (EOAEs) were recorded twice in 20 ears of 15 newborns. The recordings were performed in a room of the well baby ward, using the ILO88 in its default setting, i.e. with click stimulation. On the first test occasion, the infants were between 3 and 51 h of age, and EOAEs were identified in 10 ears. On the second test occasion, while the infants were at least 1 day older (range 42-107 h), EOAEs were present in all ears. The second EOAE was stronger, so the EOAE appeared to grow in the first days postpartum. This might be due to middle ear clearance of amniotic fluid, shortly after birth. The results of the EOAEs of the second examination were compared with 10 EOAEs in adult ears. The response levels of the newborns were significantly higher than in the adults. The (cross)-correlation peak value of the two tests' waveforms is over 0.75, however sometimes only after filtering around the most pronounced emission frequencies. The study proves that newborns failing the EOAE screen in the first 24 h after birth can pass if retested 1 day later, simply because of growth of EOAE strength.

In this study, the frequency specificity of the auditory brainstem response (ABR) threshold to. a click masked with 1590-Hz high-pass masking noise is compared with the frequency specificity of the unmasked click-evoked ABR threshold. The ABR threshold to the high-pass-noise-masked click stimulus is low frequency specific and corresponds with the 1 000-Hz pure-tone threshold. Although the ABR threshold to the unmasked click stimulus corresponds with the '3000'-Hz pure-tone threshold, the frequency specificity seems much less pronounced than that of the low-frequency-specific stimulus. This study shows, however, that this apparent lack of frequency specificity can be attributed to the selection of pure-tone hearing losses. The ABR threshold evoked by an unmasked click stimulus is, therefore, preeminently useful as a high-frequency point of a two-point audiogram. The possible reasons why the ABR threshold evoked by a broad-band stimulus as the unmasked click corresponds with the higher frequencies of the pure-tone audiogram are discussed.

Hearing function of 35 institutionalized persons with Down syndrome, age 35 to 62 years, was assessed by means of otoscopy, impedance audiometry, brainstem evoked response audiometry, and pure tone audiometry. Using brainstem evoked response audiometry, we determined response thresholds for 59 ears, which compares favorably with pure tone audiometry (20 ears). We found hearing losses of 20 dB to over 90 dB in 56 of these ears. Hearing loss should be considered and, whenever feasible, excluded as a contributing factor in social and mental deterioration in middle-age persons with Down syndrome.

Monaural and binaural auditory brainstem response (ABR) thresholds to clicks masked by high-pass noise with a cut-off frequency of 1,590 Hz were measured in normal-hearing subjects. In sleeping normal-hearing subjects, the 1,000-Hz frequency-specific ABR threshold for binaural stimulation amounted to 12 dB nHL and for monaural stimulation to 18 dB nHL. No significant difference in latency was found between monaural and binaural stimulation. Binaural ABR threshold was 5.5 +/- 1.4 dB (mean +/- SEM) lower than the mean monaural ABR threshold. This difference is statistically significant (Student's t test; p less than 0.005).

In normal-hearing subjects and in subjects with a flat cochlear hearing loss, auditory brainstem responses (ABR) were recorded at various levels of a 1,000-Hz filtered click stimulus with and without high-pass filtered masking noise. The difference in latency of the major peak in the ABR for the masked and unmasked condition was zero at the ABR threshold. We regard this as proof of the frequency specificity of the 1,000-Hz filtered click-stimulated ABR threshold. The difference between ABR threshold and the subjective puretone threshold at 1,000 Hz amounted to 19 dB in normal-hearing subjects and to 10 dB in subjects with a flat cochlear hearing loss. This is probably related to loss of temporal integration and an abnormal loudness growth (recruitment).

In normal-hearing subjects and in subjects with a flat cochlear hearing loss, auditory brainstem responses (ABR) were recorded at various levels of a 1,000-Hz filtered click stimulus with and without high-pass filtered masking noise. The difference in latency of the major peak in the ABR for the masked and unmasked condition was zero at the ABR threshold. We regard this as proof of the frequency specificity of the 1,000-Hz filtered click-stimulated ABR threshold. The difference between ABR threshold and the subjective puretone threshold at 1,000 Hz amounted to 19 dB in normal-hearing subjects and to 10 dB in subjects with a flat cochlear hearing loss. This is probably related to loss of temporal integration and an abnormal loudness growth (recruitment).

A comparison between pure-tone audiometry and brainstem electric response audiometry was made in 25 children with a conductive hearing loss due to otitis media with effusion. Pure-tone audiometry, including bone and air-conduction thresholds, was recorded using standard procedures. BERA was used to construct a latency-intensity function and from this the conductive hearing loss could be estimated. For all frequencies except for 2000 Hz a good correlation was found between the conductive loss in the pure-tone audiogram and the conductive loss as estimated by BERA. The moderate correlation for 2000 Hz is due to a ‘Carhart’ -notch-like phenomenon in the pure-tone audiogram.

Three aspects of brainstem response audiometry were investigated in the present study. (1) The brainstem response threshold was compared with the pure-tone audiogram in 40 patients with conductive hearing loss. The brainstem response threshold has a one-to-one relationship with the mean of the pure-tone thresholds at 2 and 4 kHz. The correlation coefficient in this comparison is 0.84 and the standard error of the estimate is 8.3 dB. Taking into account corresponding results in cochlear hearing loss [Drift et al.: Audiology 26: 1-10, 1987] it is concluded that the brainstem response threshold provides a good estimate of the amount of peripheral hearing loss, independent of the type of hearing loss. (2) It was shown [Drift et al.: Audiology 27: 260-270, 1988] that different types of peripheral hearing loss can be distinguished reliably with brainstem response audiometry. Parameters relevant for this distinction were the horizontal shift of the latency-level curve (1(L) curve), that of its derivative and the response threshold. In the clinical situation measurement of the response threshold is not always possible due to restlessness of the patient. To simulate this situation we randomly truncated the lower parts of the 1(L) curves of quiet patients. The test group consisted of 22 adult normally hearing subjects, 79 patients with cochlear hearing loss, 40 with conductive hearing loss and 22 with mixed hearing loss. Linear discriminant analysis was applied to the horizontal shift of the 1(L) curve and of its derivative. The brainstem diagnosis 'normal hearing' correctly excludes a conductive hearing loss in 98% of the cases and the brainstem diagnosis 'cochlear hearing loss' does so in 79%. The brainstem diagnosis 'conductive hearing loss' correctly predicts a conductive component of hearing loss in 94% of the cases and the brainstem diagnosis 'mixed hearing loss' does so in 90%. The distinction between cochlear hearing loss and normal hearing is not reliable, neither is the distinction between conductive and mixed hearing loss. (3) The amount of the conductive component of hearing loss can be estimated by the horizontal shift of the 1(L) curve. Statistical comparison with the mean of the air-bone gaps at 2 and 4 kHz gave a correlation coefficient of 0.77, a standard error of the estimate of 9.7 dB, and a slope of the regression line of 0.93. An overestimation of about 7 dB has to be taken into account in case of mixed hearing loss.

In the companion paper [V.d. Drift et al.; Audiology 27: 260-270, 1988], it was shown graphically that conductive and cochlear hearing loss can be distinguished on the basis of the combinations of the auditory brainstem response threshold with the horizontal shift of the latency-level curve of peak V, its derivative or the latency of peak V at threshold level, respectively. In addition to the patient data used in the companion paper, 22 patients with mixed hearing loss were enrolled in the present study. The statistical technique of discriminant analysis was applied to find the optimum linear combination of auditory brainstem response data for classification of a hearing loss. The brainstem classification 'cochlear hearing loss' agrees with the diagnosis on the basis of the pure-tone audiogram in 85% of the cases. In cases with the brainstem classification 'conductive hearing loss', 93% showed at least a conductive component in the pure-tone audiogram.

The auditory brainstem response thresholds and the latency-level curves, l(L)curves, for peak V were determined in 22 subjects with normal hearing, in 40 patients with conductive hearing loss and in 79 patients with cochlear hearing loss. The goal of this study was to investigate the potentials to distinguish between different types of hearing loss on the basis of these auditory brainstem responses. For this purpose the horizontal shift of the l(L) curve, the horizontal shift of its derivative and the latency of peak V at threshold level were plotted against the response threshold. For response thresholds above 30 dB nHL both the horizontal shift of the l(L) curve and the horizontal shift of its derivative give a good separation between cochlear and conductive hearing loss. The combination of the response threshold with the shift of the derivative of the l(L) curve gave a slightly better separation than that of the response threshold with the shift of the l(L) curve itself.