Daphne Ari-Even Roth

Reduced Medial Olivocochlear Bundle System Function in Children with Auditory Processing Disorders

A common complaint of children with auditory processing disorders (APD) is difficulty in understanding speech in the presence of background noise. Evidence from animal and human studies has suggested that the medial olivocochlear bundle (MOCB) may play a role in hearing in noise. The MOCB function can be evaluated by the suppression effect of the transient evoked otoacoustic emissions (TEOAE) in response to contralateral acoustic stimulation (CAS). The present study was conducted to investigate the suppression effect of TEOAE in APD children. The study groups comprised 15 APD children aged 8–13 years associated with learning disabilities and 15 controls matched for gender and age. The suppression effect of TEOAE was evaluated by comparing the TEOAE levels with and without CAS. A significantly reduced suppression effect of TEOAE was demonstrated in the APD group, when compared to the controls. In addition, higher TEOAE levels were found in the APD group, suggesting inherent reduced MOCB activity on the outer hair cells in APD children. These results imply that some APD children present low activity of the MOCB system, which may indicate a reduced auditory inhibitory function and affect their ability to hear in the presence of background noise.

A latent consolidation phase in auditory identification learning: Time in the awake state is sufficient

Large gains in performance, evolving hours after practice has terminated, were reported in a number of visual and some motor learning tasks, as well as recently in an auditory nonverbal discrimination task. It was proposed that these gains reflect a latent phase of experience-triggered memory consolidation in human skill learning. It is not clear, however, whether and when delayed gains in performance evolve following training in an auditory verbal identification task. Here we show that normal-hearing young adults trained to identify consonant-vowel stimuli in increasing levels of background noise showed significant, robust, delayed gains in performance that became effective not earlier than 4 h post-training, with most participants improving at more than 6 h post-training. These gains were retained for over 6 mo. Moreover, although it has been recently argued that time including sleep, rather than time per se, is necessary for the evolution of delayed gains in human perceptual learning, our results show that 12 h post-training in the waking state were as effective as 12 h, including no less than 6 h nights sleep. Altogether, the results indicate, for the first time, the existence of a latent, hours-long, consolidation phase in a human auditory verbal learning task, which occurs even during the awake state.

Evidence for Atypical Auditory Brainstem Responses in Young Children with Suspected Autism Spectrum Disorders.

Aim  The aim of this study was to characterize the auditory brainstem responses (ABRs) of young children with suspected autism spectrum disorders (ASDs) and compare them with the ABRs of children with language delay and with clinical norms.

Preauricular Skin Tags and Ear Pits Are Associated With Permanent Hearing Impairment in Newborns

OBJECTIVES. Our goals were to (1) study the prevalence of hearing impairment in a large cohort of infants with preauricular skin tags or ear pits and compare it with that among all other newborns participating in our universal newborn hearing screening program during the same period and (2) evaluate the effectiveness of transient evoked otoacoustic emissions as a hearing-screening tool in this population. PATIENTS AND METHODS. During the study period of 7.5 years, 68484 infants were screened for hearing impairment, of whom 637 (0.93%) had preauricular skin tags and/or ear pits. The population was divided into 3 groups: (1) a low-risk group for hearing impairment; (2) a high-risk group for hearing impairment; and (3) a very high-risk group for hearing impairment. The screening results and audiological follow-up for these infants were examined retrospectively. RESULTS. A significantly higher prevalence of permanent hearing impairment was found among infants with preauricular skin tags or ear pits (8 of 1000), compared with infants without tags or pits (1.5 of 1000). In the low-risk group, the prevalence was 3.4 of 1000, compared with 0.5 of 1000 in infants with and without preauricular tags or pits, respectively. In the high-risk group, the prevalence was 77 of 1000, compared with 20 of 1000 in infants with and without preauricular tags or pits, respectively. The odds ratio for hearing impairment associated with preauricular skin tags and/or ear pits after adjusting for level of risk group was 4.9. All infants diagnosed with permanent hearing impairment, with the exception of 1 with late-onset impairment, were detected by in-hospital transient-evoked otoacoustic emissions screening. CONCLUSIONS. Infants with preauricular skin tags or ear pits are at increased risk for permanent hearing impairment. Transient-evoked otoacoustic emissions were found to be an effective hearing-screening tool in this population.

Universal neonatal cytomegalovirus screening using saliva – Report of clinical experience

OBJECTIVES To analyze the results of a neonatal universal screen for congenital cytomegalovirus (CMV) using saliva real-time polymerase chain reaction (rt-PCR). STUDY DESIGN During one year (15/5/2011-15/5/2012), saliva was collected from 9845 infants (97% of 10,137 newborns). Viral DNA was extracted by Magna-Pure LC (Roche) and was tested for the presence of CMV IE and gB genes. Urine culture was collected from positive infants for confirmation. For all infants with congenital CMV maternal data were collected and head ultrasound, blood count, liver enzymes, retinal examination and auditory brainstem response testing were performed. Parents were notified in advance and had the option to avoid screening. The ethical committee approved retrospective analysis of the data. RESULTS Fifty six infants (0.57%) had a positive saliva assay. Of these, 47 were confirmed by urine rt-PCR and culture, in another one maternal sero-conversion was documented during pregnancy (48 infants). Twenty-eight mothers (28/47, 60%) had primary infection during pregnancy, 14 (30%) had non-primary infection, and no serological data were obtained from five (10%). Four infants (8.5%), two with prenatal diagnosis of CMV and normal fetal brain imaging and two born to mothers sero-positive before pregnancy, exhibited symptoms related to CMV and were offered antivirals. Hearing impairment was diagnosed in two infants (late onset HI in one case). CONCLUSIONS Saliva rt-PCR assay is a feasible and effective means of universal neonatal CMV screening that can detect affected infants who might benefit from treatment and follow-up. The long-term clinical significance of screening and its cost effectiveness are yet to be determined.

Prolonged auditory brainstem responses in infants with autism.

Numerous studies have attempted to identify early physiological abnormalities in infants and toddlers who later develop autism spectrum disorder (ASD). One potential measure of early neurophysiology is the auditory brainstem response (ABR), which has been reported to exhibit prolonged latencies in children with ASD. We examined whether prolonged ABR latencies appear in infancy, before the onset of ASD symptoms, and irrespective of hearing thresholds. To determine how early in development these differences appear, we retrospectively examined clinical ABR recordings of infants who were later diagnosed with ASD. Of the 118 children in the participant pool, 48 were excluded due to elevated ABR thresholds, genetic aberrations, or old testing age, leaving a sample of 70 children: 30 of which were tested at 0–3 months, and 40 were tested at toddlerhood (1.5–3.5 years). In the infant group, the ABR wave‐V was significantly prolonged in those who later developed ASD as compared with case‐matched controls (n = 30). Classification of infants who later developed ASD and case‐matched controls using this measure enabled accurate identification of ASD infants with 80% specificity and 70% sensitivity. In the group of toddlers with ASD, absolute and interpeak latencies were prolonged compared to clinical norms. Findings indicate that ABR latencies are significantly prolonged in infants who are later diagnosed with ASD irrespective of their hearing thresholds; suggesting that abnormal responses might be detected soon after birth. Further research is needed to determine if ABR might be a valid marker for ASD risk. Autism Res 2016, 9: 689–695.

Delay in auditory behaviour and preverbal vocalization in infants with unilateral hearing loss.

To evaluate the impact of unilateral hearing loss (UHL) on early aural/oral communication skills of infants by comparing performance to infants with bilateral normal hearing (BNH).

Frequency discrimination training: is there ear symmetry?

While it is well documented that significant improvements in a frequency discrimination task occur following training of normal-hearing adult subjects, less is known about the symmetry between the ears. The objectives of the present study were (1) to compare the first obtained DLF thresholds between left and right ears, (2) to determine whether single-session training would result in similar improvements in those subjects trained in the right ear versus those trained in the left ear, and (3) to evaluate the generalization of learning to the untrained ear and compare its extent between the left and right ears. Two groups of 10 normal-hearing subjects participated in a single-session training. One group of 10 subjects was trained in the left ear and the second group of 10 additional subjects was trained in the right ear. Single-session training consisted of 10 difference limen frequency (DLF) thresholds for 1 kHz using a two-interval, two-alternative forced choice paradigm. Generalization to the untrained ear was tested 24 hours post-training. Our results show that: (1) No significant differences were found in the first obtained DLF thresholds between left and right ears; (2) Similar improvement in DLF thresholds occurred in both ears for single-session training; and (3) Twenty-four hours post-training, learning generalized to the untrained ear with similar generalization to both ears. Future studies are required in order to establish whether this symmetry is maintained with verbal stimuli and/or after multi-session training.

Evidence for a right cochlear implant advantage in simultaneous bilateral cochlear implantation.

To compare speech perception performance with right versus left cochlear implants (CIs) in children with bilateral CIs implanted simultaneously.

Frequency discrimination thresholds: the effect of increment versus decrement detection of frequency.

Difference limen for frequency (DLF) is traditionally tested using a frequency increment detection paradigm in which listeners are requested to distinguish between a reference tone and a series of comparison tones of higher frequency. Sporadic findings indicated that an increment paradigm is not necessarily comparable to a decrement paradigm, in which the comparison tones are lower than the reference tone. The purpose of the present study was to test whether the ability to detect frequency increments is different from that of frequency decrements. DLFs of 16 young women were measured at 200 Hz and 1,000 Hz, using detection of both frequency increment and decrement paradigms. Results indicated that: (1) the frequency increment detection paradigm was significantly smaller (i.e., superior) to the decrement paradigm for the DLF task at 200 Hz, (2) for both frequencies, the number of participants who exhibited better DLF using the frequency increment detection paradigm was significantly larger than the number of those who had better DLFs using the frequency decrement paradigm, and (3) for both frequencies, strong correlations were found between DLFs obtained in the increment versus the decrement paradigms. These results have implications: (1) to studies whose subjects may have reduced sensitivities at frequencies higher than the reference tone (such as the hearing impaired), and (2) to models related to the role of auditory feedback on voice accuracy and to the underlying processes of frequency discrimination.