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Abstract: Objective: With more children receiving cochlear implants at an early age, there is a need for evaluation and assessment of early auditory behavior. We present the translation of the LittlEARS® Auditory Questionnaire into Hebrew and into Arabic. First the validation of the LittlEARS® Auditory Questionnaire in normal hearing children was evaluated. Second, the auditory behavior and the progress in hearing skills of a group of children with cochlear implants were assessed. Methods: A “back-translation” method was used to translate and adapt the LittlEARS® Auditory Questionnaire into Hebrew and into Arabic. Normal hearing participants included 70 Hebrew speaking and 97 Arabic speaking parents of children from 1 to 24 months of age with normal hearing. An additional group of 42 parents of children with cochlear implants with a hearing age of up to 24 months completed the LittlEARS® Auditory Questionnaire. 27 of them completed the questionnaire more than once at intervals, so that change and development could be recorded. Scores on the LittlEARS® Auditory Questionnaire were compared to results of SIR and CAP scales and other available auditory data. Results: The results of the first study show that the curves found for the Hebrew and the Arabic translations of the LittlEARS® Auditory Questionnaire are essentially similar to those previously found for other languages. These curves reflect the age dependency of auditory skills. Furthermore, in the group with cochlear implants the developmental pattern was different than that of the normal hearing group, with an initial steep increase and a later slower improvement. This trend appeared both in curves of groups and in curves of individuals (individuals whose parents completed the questionnaire at several points in time). There was a high correlation between scores on the LittlEARS® Auditory Questionnaire and results of other audiologic tests, showing validity of results with the LittlEARS® Auditory Questionnaire. Conclusion: Both the Hebrew and Arabic versions of the LittlEARS® Auditory Questionnaire were found to be reliable and valid tools for assessment of the development of auditory behavior in children up to the age of 24 months. Furthermore, the LittlEARS® Auditory Questionnaire in both languages is useful in monitoring the progress of children with cochlear implant. [Copyright &y& Elsevier]

Air and bone conduction thresholds are used to differentiate between conductive and sensori-neural hearing losses because bone conduction is thought to bypass the conductive apparatus, directly activating the inner ear. However, the suggested bone conduction mechanisms involve the outer and middle ears. Also, normal bone conduction thresholds have been reported in cases of lesions to the conduction pathway. Therefore, further investigation of bone conduction mechanisms is required.

Congenital cytomegalovirus (cCMV) is the most common intrauterine infection, leading to neurodevelopmental disabilities. Universal newborn infant screening of cCMV has been increasingly advocated. In the absence of a high-throughput screening test, which can identify all infected newborn infants, the development of an accurate and efficient testing strategy has remained an ongoing challenge. Here we assessed the implementation of pooled saliva polymerase chain reaction (PCR) tests for universal screening of cCMV, in two hospitals of Jerusalem from April 2022 through April 2023. During the 13-month study period, 15,805 infants (93.6% of all live newborn infants) were screened for cCMV using the pooled approach that has since become our routine screening method. The empirical efficiency of the pooling was six (number of tested newborn infants per test), thereby sparing 83% of the saliva tests. Only a minor 3.05 PCR cycle loss of sensitivity was observed for the pooled testing, in accordance with the theoretical prediction for an eight-sample pool. cCMV was identified in 54 newborn infants, with a birth prevalence of 3.4 per 1,000; 55.6% of infants identified with cCMV were asymptomatic at birth and would not have been otherwise targeted for screening. The study demonstrates the wide feasibility and benefits of pooled saliva testing as an efficient, cost-sparing and sensitive approach for universal screening of cCMV., (© 2024. The Author(s).)

Soft tissue conduction is a mode of hearing which differs from air and bone conduction since the soft tissues of the body convey the audio-frequency vibrations to the ear. It is elicited by inducing soft tissue vibrations with an external vibrator applied to sites on the body or by intrinsic vibrations resulting from vocalization or the heartbeat. However, the same external vibrator applied to the skin sites also excites cutaneous mechanoreceptors, and attempts have been made to assist patients with hearing loss by audio-tactile substitution. The present study was conducted to assess the contribution of the auditory nerve and brainstem pathways to soft tissue conduction hearing. The study involved 20 normal hearing students, equipped with ear plugs to reduce the possibility of their response to air-conducted sounds produced by the external vibrator. Pure tone audiograms and speech reception (recognition) thresholds were determined in response to the delivery of the stimuli by a clinical bone vibrator applied to the cheek, neck and shoulder. Pure tone and speech recognition thresholds were obtained; the participants were able to repeat the words they heard by soft tissue conduction, confirming that the auditory pathways in the brain had been stimulated, with minimal involvement of the somatosensory pathways.

BACKGROUNDCytomegalovirus (CMV) is the most common intrauterine infection, leading to infant brain damage. Prognostic assessment of CMV-infected fetuses has remained an ongoing challenge in prenatal care, in the absence of established prenatal biomarkers of congenital CMV (cCMV) infection severity. We aimed to identify prognostic biomarkers of cCMV-related fetal brain injury.METHODSWe performed global proteome analysis of mid-gestation amniotic fluid samples, comparing amniotic fluid of fetuses with severe cCMV with that of asymptomatic CMV-infected fetuses. The levels of selected differentially excreted proteins were further determined by specific immunoassays.RESULTSUsing unbiased proteome analysis in a discovery cohort, we identified amniotic fluid proteins related to inflammation and neurological disease pathways, which demonstrated distinct abundance in fetuses with severe cCMV. Amniotic fluid levels of 2 of these proteins - the immunomodulatory proteins retinoic acid receptor responder 2 (chemerin) and galectin-3-binding protein (Gal-3BP) - were highly predictive of the severity of cCMV in an independent validation cohort, differentiating between fetuses with severe (n = 17) and asymptomatic (n = 26) cCMV, with 100%-93.8% positive predictive value, and 92.9%-92.6% negative predictive value (for chemerin and Gal-3BP, respectively). CONCLUSIONAnalysis of chemerin and Gal-3BP levels in mid-gestation amniotic fluids could be used in the clinical setting to profoundly improve the prognostic assessment of CMV-infected fetuses.FUNDINGIsrael Science Foundation (530/18 and IPMP 3432/19); Research Fund - Hadassah Medical Organization.

Soft tissue conduction is an additional mode of auditory stimulation which can be initiated either by applying an external vibrator to skin sites not overlying skull bone such as the neck (so it is not bone conduction) or by intrinsic body vibrations resulting, for example, from the heartbeat and vocalization. The soft tissue vibrations thereby induced are conducted by the soft tissues to all parts of the body, including the walls of the external auditory canal. In order for soft tissue conduction to elicit hearing, the soft tissue vibrations which are induced must penetrate into the cochlea in order to excite the inner ear hair cells and auditory nerve fibers. This final stage can be achieved either by an osseous bone conduction mechanism, or, more likely, by the occlusion effect: the vibrations of the walls of the occluded canal induce air pressures in the canal which drive the tympanic membrane and middle ear ossicles and activate the inner ear, acting by means of a more air conduction-like mechanism. In fact, when the clinician applies his stethoscope to the body surface of his patient in order to detect heart sounds or pulmonary air flow, he is detecting soft tissue vibrations.

To gain insight into the broader implications of the occlusion effect (OE-difference between unoccluded and occluded external canal thresholds), the OE in response to pure tones at 0.5, 1.0, 2.0 and 4.0 kHz to two bone conduction sites (mastoid and forehead) and two soft tissue conduction (STC) sites (under the chin and at the neck) were assessed. The OE was present at the soft tissue sites and at the bone conduction sites, with no statistical difference between them. The OE was significantly greater at lower frequencies, and negligible at higher frequencies. It seems that the vibrations induced in the soft tissues (STC) during stimulation at the soft tissue sites are conducted not only to the inner ear and elicit hearing, but also reach the walls of the external canal and initiate air pressures in the occluded canal which drive the tympanic membrane and excite the inner ear, leading to hearing. Use of a stethoscope by the internist to hear intrinsic body sounds (heartbeat, blood flow) serves as a clear demonstration of STC and its relation to hearing.

Background and Objectives: Hearing can be elicited in response to vibratory stimuli delivered to fluid in the external auditory meatus. To obtain a complete audiogram in subjects with normal hearing in response to pure tone vibratory stimuli delivered to fluid applied to the external meatus. Subjects and., Methods: Pure tone vibratory stimuli in the audiometric range from 0.25 to 6.0 kHz were delivered to fluid applied to the external meatus of eight participants with normal hearing (15 dB or better) using a rod attached to a standard clinical bone vibrator. The fluid thresholds obtained were compared to the air conduction (AC), bone conduction (BC; mastoid), and soft tissue conduction (STC; neck) thresholds in the same subjects., Results: Fluid stimulation thresholds were obtained at every frequency in each subject. The fluid and STC (neck) audiograms sloped down at higher frequencies, while the AC and BC audiograms were flat. It is likely that the fluid stimulation audiograms did not involve AC mechanisms or even, possibly, osseous BC mechanisms., Conclusions: The thresholds elicited in response to the fluid in the meatus likely reflect a form of STC and may result from excitation of the inner ear by the vibrations induced in the fluid. The sloping fluid audiograms may reflect transmission pathways that are less effective at higher frequencies.

Objective: The object of this study was to explore how parents experienced receiving the news of their child's hearing loss, and how audiologists experienced the situation of conveying the diagnosis, in order to examine improvements to the current process., Method: A questionnaire regarding different aspects of breaking the news was developed. 48 Arabic and Hebrew speaking parents of hearing impaired children answered the questionnaire. A similar questionnaire was filled out by 31 audiologists., Results: Findings demonstrate parents' general satisfaction with the manner in which the diagnosis was delivered. According to the parents' reports, receiving the diagnosis evoked negative feelings of fear, depression and difficulty believing the diagnosis. Parents' feelings were influenced by their cultural background, such as their ethnic identity, religious practice and difficulties due to language barriers. The audiologists described concern and anxiety when breaking bad news, but they felt they were able to present the diagnosis. The audiologists felt that they were not trained in this aspect, and the ability was acquired through experience. Both parents and audiologists agreed that the audiologist should be the professional to deliver the diagnosis. All emphasized sensitivity and professionalism as necessary qualities. Whereas audiologists were of the opinion that the most important information to transmit was the type of hearing loss, the parents were most interested in discussing their feelings, the rehabilitation process, and talking to other parents., Conclusions: Overall, results reveal that breaking bad news of a child's hearing loss has been done fairly well. Due to the parents' reports of the need for emotional support, it is suggested that audiologists receive further training and adjust to personal and cultural differences. Recommendations include establishing an appropriate setting and ensuring that an interpreter is available when necessary. Further emotional support may be provided through establishment of a family support network., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Hearing can be induced not only by airborne sounds (air conduction [AC]) and by the induction of skull vibrations by a bone vibrator (osseous bone conduction [BC]), but also by inducing vibrations of the soft tissues of the head, neck, and thorax. This hearing mode is called soft tissue conduction (STC) or nonosseous BC., Purpose: This study was designed to gain insight into the mechanism of STC auditory stimulation., Research Design: Fluid was applied to the external auditory canal in normal participants and to the mastoidectomy common cavity in post-radical mastoidectomy patients. A rod coupled to a clinical bone vibrator, immersed in the fluid, delivered auditory frequency vibratory stimuli to the fluid. The stimulating rod was in contact with the fluid only. Thresholds were assessed in response to the fluid stimulation., Study Sample: Eight ears in eight normal participants and eight ears in seven post-radical mastoidectomy patients were studied., Data Collection and Analysis: Thresholds to AC, BC, and fluid stimulation were assessed. The postmastoidectomy patients were older than the normal participants, with underlying sensorineural hearing loss (SNHL). Therefore, the thresholds to the fluid stimulation in each participant were corrected by subtracting his BC threshold, which expresses any underlying SNHL., Results: Hearing thresholds were obtained in each participant, in both groups in response to the fluid stimulation at 1.0 and 2.0 kHz. The fluid thresholds, corrected by subtracting the BC thresholds, did not differ between the groups at 1.0 kHz. However, at 2.0 kHz the corrected fluid thresholds in the mastoidectomy patients were 10 dB lower (better) than in the normal participants., Conclusions: Since the corrected fluid thresholds at 1.0 kHz did not differ between the groups, the response to fluid stimulation in the normal participants at least at 1.0 kHz was probably not due to vibrations of the tympanic membrane and of the ossicular chain induced by the fluid stimulation, since these structures were absent in the mastoidectomy patients. In addition, the fluid in the external canal (normal participants) and the absence of the tympanic membrane and the ossicular chain (mastoidectomy patients) induced a conductive hearing loss (threshold elevation to air-conducted sounds coming from the bone vibrator), so that AC mechanisms were probably not involved in the thresholds to the fluid stimulation. In addition, as a result of the acoustic impedance mismatch between the fluid and skull bone, the audio-frequency vibrations induced in the fluid at threshold would probably not lead to vibrations of the bony wall of the meatus, so that hearing by osseous BC is not likely. Therefore, it seems that the thresholds to the fluid stimulation, in the absence of AC and of osseous BC, represent an example of STC, which is an additional mode of auditory stimulation in which the cochlea is activated by fluid pressures transmitted along a series of soft tissues, reaching and exciting the inner ear directly. STC can explain the mechanism of several auditory phenomena., (American Academy of Audiology)

Background: Osseous bone conduction (BC) stimulation involves applying the clinical bone vibrator with an application force of about 5 Newton (N) to the skin over the cranial vault of skull bone (e.g., mastoid, forehead). In nonosseous BC (also called soft tissue conduction), the bone vibrator elicits hearing when it is applied to skin sites not over the cranial vault of skull bone, such as the neck., Purpose: To gain insight into the mechanisms of osseous and nonosseous BC., Research Design: In general, thresholds were determined with the bone vibrator applied with about 5 N force directly to osseous sites (mastoid, forehead) on the head of the participants, as classically conducted in the clinic, and again without direct physical contact (i.e., 0 N force) achieved by coupling the bone vibrator to gel as in ultrasound diagnostic imaging, on the same or nearby skin sites (nonosseous BC). The participants were equipped with earplugs to minimize air-conducted stimulation., Study Sample: In the first experiment, 10 normal-hearing participants were tested with stimulation (5 and 0 N) at the forehead; in the second experiment, 10 additional normal-hearing participants were tested with stimulation at the mastoid (about 5 N) and at the nearby tragus and cavum concha of the external ear (0 N)., Results: The mean thresholds with 0 N were much better than might be expected from classical theories in response to stimulation by a bone vibrator, in the absence of any application force. The differences between the mean thresholds with the 0 N and the 5 N forces depended on condition, site, and stimulus frequency of the comparisons. The difference was 1.5 dB at 1.0 kHz on the forehead; ranged between 10 and 12.5 dB at 1.0 kHz on the cavum and tragus (versus on the mastoid) and at 2.0 and 4.0 kHz on the forehead; 17 and 19 dB at 2.0 kHz on the cavum and tragus (versus on the mastoid); reaching 32 dB only in a single condition (forehead at 0.5 kHz)., Conclusions: As it is unlikely that threshold intensity stimulation delivered with 0 N application force could have induced vibrations of the underlying or nearby bone, inducing osseous BC, the relatively low thresholds in the absence of any application force, together with the small differences between the thresholds with 0 N (gel/soft tissue, nonosseous) and 5 N force (osseous BC) lead to the suggestion that in most situations, the BC thresholds actually represent the nonosseous (soft tissue conduction) thresholds at the stimulation site., (American Academy of Audiology.)

Background: The aim of this study was to describe the results of the Auditory Behavior in Everyday Life (ABEL) questionnaire adapted to Hebrew and to Arabic and its association to clinical test results in children with cochlear implants. As assessment of hearing by audiometry does not always adequately reflect performance in daily life, questionnaires have been developed to assess functioning in natural surroundings and to track progress. In order to evaluate cochlear-implanted children's verbal and communicative abilities, the parental ABEL questionnaire was developed in 2002. The advantages of the ABEL questionnaire are that it is intended for a wide age range, is quick to administer, and is filled out by parents themselves., Methods: The ABEL questionnaire was translated into Hebrew and into Arabic and routinely used in the clinic. A total of 61 questionnaires were thus filled out by parents of children with cochlear implants (ages 3.9-14.3 years) when they came for routine mapping. Retrospectively, data were analyzed and questionnaire results were compared with performance with the implant on several clinical tests: audiometric thresholds, discrimination (percentage) of vowel-consonant-vowel nonsense syllables, and results of speech perception tests with monosyllabic and bisyllabic words and with sentences in quiet and in noise., Results: A correlation was found between the different sections of the questionnaire, and age at implantation had a significant effect on questionnaire scores. However, correlations between questionnaire score and clinical tests were found only for speech perception tests in noise and not in quiet or to audiogram and speech reception threshold., Conclusions: As has been reported previously, self-evaluation or parental evaluation does not always correlate with all measured results of hearing performance. However, the subjective information collected through questionnaires can be valuable for evaluation of progress, for counseling and rehabilitation training, as well as for mapping.

Background: Implantation at a young age enables exposure to language and speech during the critical age for language acquisition. Long duration of auditory deprivation may lead to less optimal results., Methods: A retrospective review of cases was performed. A young girl with congenital bilateral profound sensorineural hearing loss received her first cochlear implant on the right side at the age of 2½ years and successfully developed good speech and language. At the age of 10 years, explantation had to be performed, and as reimplantation could not be done on the same side, the implantation was done on the left ear, which had never received auditory stimulation. Two age-matched girls with bilateral sequential implantation, in whom the second sound-deprived ear was implanted after a long duration, were studied as well., Results: A year after implantation, in two of the cases there was very good speech perception, even in noise. In one case, the second ear never attained the ability to understand speech., Conclusions: These results can be explained in light of recent findings that early unilateral stimulation can result in bilateral representation in the auditory cortex.

Background: Audiologists mapping in the clinic report that many cochlear-implanted teenagers and their parents complain of deterioration in hearing capabilities. The aim of this study was to compare the mapping parameters measured over the years and determine whether more changes occurred throughout adolescence than during childhood., Methods: The files of 23 cochlear-implanted teenagers were studied retrospectively. Data were collected for each individual at several time points between the ages of 6.5 and 18.25 years. Typical data collected from the mapping sessions included behaviorally measured T values, impedance results, audiogram thresholds in the free field with the implant, speech reception threshold, and speech perception of vowel-consonant-vowel syllables., Results: No changes were found in either the behavioral or the objective parameters over the years., Conclusions: The stability in mapping and audiometric measurements found in adolescence do not support an explanation based on hormonal and growth effects on implant function. Perhaps a more likely cause of the subjective sense of hearing deterioration is related to changes in social and educational requirements.

Background: Auditory sensation can be elicited not only by air conduction (AC) with an earphone and by bone conduction by applying a bone vibrator to bony sites on the head, but also by a newly described mode based on applying the bone vibrator to soft tissue sites on the head, neck, and thorax (soft tissue conduction - STC). This study was designed to assess whether it is necessary to compress the skin at the STC sites, which could induce vibrations of the underlying bone., Methods: In 15 normal-hearing subjects, thresholds were assessed with the bone vibrator in air (control for possible AC), direct contact of the bone vibrator with the mastoid and regions around the lip, and indirect contact (via a cotton wool wick, dry or wet) of the bone vibrator with sites around the lip., Results: Even though the best (lowest) thresholds were obtained with direct contact, the subjects clearly heard the sound stimulation when presented only by the gentle contact of the wick with the skin, especially when the contact site was moist., Conclusions: STC stimulation does not require vibrations of the skull bone and seems to involve the transmission of auditory frequency vibrations, through a series of soft tissues, to the inner ear.

Objective: Hearing screening programs in infancy should identify hearing impairment as early as possible. The two common programs utilize either objective neonatal tests (oto-acoustic emissions (OAE) or automatic auditory brainstem responses (aABR)) or behavioral screening at 7-9 months of age. Most countries employ only one of these options. The uniqueness of this study is the comparison of both hearing screening programs on the same group of children., Methods: The study was conducted on 1545 children born between the years 1999 and 2003 who were followed up in public well baby clinics in the Jerusalem district. The children were tested with transient oto-acoustic emissions (TEOAE) before discharge from the neonatal ward, and later, at the age of 7-9 months, underwent a behavioral hearing screening test in a public well baby clinic. The results of both hearing screening programs were compared., Results: The compliance rates were 99.7% for the neonatal testing and 83% for the 7-9 months behavioral testing (p=0.0001). The failure rate was 4-6% in both screening programs; failure of OAE testing was unilateral in 65% of newborns; at 7-9 months bilateral failure was more common (56%). There was an 11.2% disagreement (kappa coefficient 0.03) between the outcomes of both tests. In another group of 49 known hearing-impaired children, 27 who had undergone newborn screening were diagnosed before the age of behavioral testing. Twelve children had failed either both tests or the only test they underwent. In nine cases, the children had passed one of the hearing screening tests and had failed the other, and one child had passed both tests., Conclusions: Newborn hearing screening has the advantages of objectivity, early identification, and higher compliance. The major advantage of the later behavioral test is identification of later onset or progressive hearing impairment as well as auditory neuropathy spectrum disorder. Each screening test is testing different entities; hence they are complementary and not interchangeable or superfluous. We recommend a comprehensive two-step hearing screening plan (newborn and later behavioral) with close cooperation between the health care providers involved., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Objective: To investigate age-related changes in speech perception by measuring event-related potentials (ERPs) elicited by auditory stimuli varying in their linguistic characteristics from pure tones to words., Methods: ERPs were recorded from 64 subjects in three age groups (young, middle age and elderly) to auditory target stimuli, using an oddball paradigm. Three different tasks and stimuli were used: tonal, phonological and semantic., Results: N100 latency to tonal targets was significantly shorter than to both types of speech targets. P300 latency to tonal targets was significantly shorter than to phonological targets, which in turn was shorter than to semantic targets. P300 amplitude recorded to the speech targets was significantly larger over the left hemisphere than over the right hemisphere in the young subjects. However, the reverse pattern of asymmetry, favoring the right hemisphere was found in the elderly subjects. The pattern of the hemispheric distribution for the middle aged was somewhere in between the young and elderly., Conclusions: The data indicate possible progressive changes in left-right asymmetry in language processing with aging., Significance: Findings may indicate an increased use of compensatory mechanisms for speech processing, or alternatively, an increased use of different generators as individuals age.

Maple syrup urine disease (MSUD) is a rare metabolic disease due to deficiency in the enzyme that breaks down branched chain amino acids. Lack of the enzyme causes accumulation of these amino acids and, if untreated, causes severe neurological damage. A case study of a 10-day old female infant, born after 40 weeks' gestation with a birthweight of 2740 g with MSUD hospitalized in the acute stage with respiratory failure and severe brain oedema is described. As part of the neurological evaluation, auditory nerve brainstem evoked response testing was conducted and revealed bilateral presence of the first wave from the auditory nerve, with no later brainstem waves. Over the course of days when her condition improved following dialysis treatment and a diet to reach balanced levels of branched chain amino acids, the later brainstem waves appeared on one side, and several weeks later they were also observed on the other side. The possible mechanisms of the reversibility of the appearance of brainstem waves in this case are discussed.

The importance of early detection of hearing loss is well known and screening programs for newborns are becoming more common throughout the world. The Hadassah hearing screening program for newborns using the Transient Evoked Otoacoustic Emission (TEOAE) test began in October 1999. All newborns are tested before discharge from the hospital. In case of inadequate results, the infant is scheduled for follow-up in 4 weeks in the Speech and Hearing Center, and according to results, a full audiological evaluation is performed. The high-risk population is also scheduled for follow-up. The preliminary results from 8,982 newborns show that 93.5% passed the screening in the maternity ward, 4.2% failed unilaterally, and 2.2% failed bilaterally. The follow-up rate was low in the beginning, and improved due to proceeding letters and phone calls. The follow-up results show that we were able to detect 6 infants with a hearing loss under the age of 3 months, 4 of these infants belong to the high-risk group. We believe that TEOAE hearing screening for newborns is feasible and can help to detect hard of hearing children earlier than in the past. Undoubtedly, cost effectiveness considerations will be involved in implementation decisions.

The development of function in the various receptors in the inner ear was studied in the neonatal rat, which is altricious with respect to hearing, using short latency evoked potentials, both auditory (ABR) and vestibular (VsEP). It was found that VsEPs could be recorded from all the vestibular end-organs by post natal day (PND) 8, whilst ABR could only be recorded from all animals on PND 14, showing the earlier onset of vestibular function in the inner ear. These results are discussed with relation to onset of inner ear function in the human fetus.

Newborns are often discharged from hospital at the age of about 48 hours. At this age, transient evoked otoacoustic emissions (TEOAEs) are not necessarily recordable in all healthy newborns. In order to determine the factors which would enable the successful recording of TEOAEs before discharge to facilitate screening for hearing, 65 fullterm newborns under 48 hours of age were tested, the youngest being 10 hours old. The ears of those neonates in whom TEOAEs could not be obtained (N = 7 neonates bilaterally, 6 unilaterally) were examined otoscopically, cleaned of vernix and retested for TEOAEs. We were thus able to record in at least one ear in all neonates tested, if the ears were clean, if they were asleep and if the testing room was quiet.

The effects of cooling rats from 37 degrees C to 27 degrees C and rewarming to 37 degrees C on the conductive mechanism of the middle ear was studied by means of acoustic impedance measurements. Cooling reduced middle ear compliance reversibly, without an effect on external canal volume and middle ear pressure. These results provide evidence for an increase in the stiffness of the tympanic membrane and/or of the ossicular chain and/or a decrease in stapes mobility. Thus a small part of the decrease in the magnitude of otoacoustic emissions during cooling is due to an effect on the conductive mechanism of the middle ear.

Based on the findings that adrenocortical hormones are involved in the regulation of Na+, K(+)-ATPase in several tissues and the presence of receptors for these hormones in the ear during auditory development, it has been suggested that these hormones also induce Na+, K(+)-ATPase activity and the endocochlear potential in the ear, leading to auditory function in the fetus-neonate. In order to test this hypothesis, glucocorticoid and mineralocorticoid hormones were injected into rat pups and their auditory development, compared to control litter-mates, was tested by recording auditory nerve-brainstem evoked potentials (ABR). Those who received glucocorticoid hormones had elevated ABR thresholds on post-natal day (PND) 9, others on PND 11 and still others on PND 16, compared to control litter-mates. The ABR thresholds of those injected with mineralocorticoids were not different from those in controls. These results and additional considerations related to the time sequence of the natural appearance of these hormones in the plasma, of their receptors in the ear and the onset of hearing in rat pups makes it extremely unlikely that adrenocortical hormones are involved in the initiation of Na+, K(+)-ATPase pumps and thereby of the endocochlear potential in the inner ear. It is possible that these hormones and their receptors play a role in the later regulation of the number of pumps.