IMPAIRED AUDITORY ATTENTION SKILLS FOLLOWING MIDDLE-EAR INFECTIONS

A Large-Scale Study of the Relationship Between Degree and Type of Hearing Loss and Recognition of Speech in Quiet and Noise

OBJECTIVES

Understanding speech in noise (SIN) is the dominant complaint of individuals with hearing loss. For decades, the default test of speech perception in routine audiologic assessment has been monosyllabic word recognition in quiet (WRQ), which does not directly address patient concerns, leading some to advocate that measures of SIN should be integrated into routine practice. However, very little is known with regard to how SIN abilities are affected by different types of hearing loss. Here, we examine performance on clinical measures of WRQ and SIN in a large patient base consisting of a variety of hearing loss types, including conductive (CHL), mixed (MHL), and sensorineural (SNHL) losses.

DESIGN

In a retrospective study, we examined data from 5593 patients (51% female) who underwent audiometric assessment at the Stanford Ear Institute. All individuals completed pure-tone audiometry, and speech perception testing of monaural WRQ, and monaural QuickSIN. Patient ages ranged from 18 to 104 years (average = 57). The average age in years for the different classifications of hearing loss was 51.1 (NH), 48.5 (CHL), 64.2 (MHL), and 68.5 (SNHL), respectively. Generalized linear mixed-effect models and quartile regression were used to determine the relationship between hearing loss type and severity for the different speech-recognition outcome measures.

RESULTS

Patients with CHL had similar performance to patients with normal hearing on both WRQ and QuickSIN, regardless of the hearing loss severity. In patients with MHL or SNHL, WRQ scores remained largely excellent with increasing hearing loss until the loss was moderately severe or worse. In contrast, QuickSIN signal to noise ratio (SNR) losses showed an orderly systematic decrease as the degree of hearing loss became more severe. This effect scaled with the data, with threshold-QuickSIN relationships absent for CHL, and becoming increasingly stronger for MHL and strongest in patients with SNHL. However, the variability in these data suggests that only 57% of the variance in WRQ scores, and 50% of the variance in QuickSIN SNR losses, could be accounted for by the audiometric thresholds. Patients who would not be differentiated by WRQ scores are shown to be potentially differentiable by SIN scores.

CONCLUSIONS

In this data set, conductive hearing loss had little effect on WRQ scores or QuickSIN SNR losses. However, for patients with MHL or SNHL, speech perception abilities decreased as the severity of the hearing loss increased. In these data, QuickSIN SNR losses showed deficits in performance with degrees of hearing loss that yielded largely excellent WRQ scores. However, the considerable variability in the data suggests that even after classifying patients according to their type of hearing loss, hearing thresholds only account for a portion of the variance in speech perception abilities, particularly in noise. These results are consistent with the idea that variables such as cochlear health and aging add explanatory power over audibility alone.

A protocol for a randomized-controlled trial to investigate the effect of infant sign training on the speech-language development in young children born with cleft palate

BACKGROUND

Children born with a cleft palate with or without cleft lip (CP ± L) are known to be at risk for speech-language disorders that impact educational and social-emotional growth. It is hypothesized that speech-language intervention delivered before the age of 3 years could decrease the impact of CP ± L on speech-language development. Infant sign training in combination with verbal input expands the natural communication of young children including multimodal speech-language input (i.e., verbal and manual input) via caregivers who act as co-therapists.

AIMS

To determine the effectiveness of infant sign training in 1-year-old children with CP ± L by comparing different interventions.

METHODS & PROCEDURES

This is a two-centre, randomized, parallel-group, longitudinal, controlled trial. Children are randomized to either an infant sign training group (IST group), a verbal training group (VT group) or no intervention control group (C group). Caregivers of children who are assigned to the IST group or VT group will participate in three caregiver training meetings to practise knowledge and skills to stimulate speech-language development. Outcome measures include a combination of questionnaires, language tests and observational analyses of communicative acts.

OUTCOMES & RESULTS

It is hypothesized that speech-language development of children with CP ± L will benefit more from IST compared with VT and no intervention. Additionally, the number and quality of communicative acts of both children and caregivers are expected to be higher after IST.

CONCLUSIONS & IMPLICATIONS

This project will contribute to the development of evidence-based clinical practice guidelines regarding early speech-language intervention in children with CP ± L under the age of 3 years.

WHAT THIS PAPER ADDS

What is already known on the subject Children with CP ± L are known to be at risk for speech-language delays that impact educational and social emotional growth. Given the limited scientific prove of the impact of early speech-language intervention, no standardized clinical practice guidelines are available yet for children with CP ± L under the age of 3 years. Early intervention in this population mostly focuses on improving verbal input via caregivers or professionals without including a multimodal language input. A growing scientific interest has been seen in the use of infant signs to support speech-language development and caregiver-child interaction in typically developing children and children with developmental delays. What this study adds to existing knowledge No evidence is yet available for the effectiveness and feasibility of early intervention based on infant sign training in combination with verbal input to improve speech-language skills in young children with CP ± L. The current project will investigate the effect of infant sign training on the speech-language development in this population. Outcome measures are compared with those of two control groups: verbal training only and no intervention. It is hypothesized that infant signs may support the intelligibility of verbal utterances produced by children with CP ± L. Improving children's intelligibility may increase the opportunities for these children to engage in early, frequent and high-quality interactions with their caregivers resulting in a richer social and linguistic environment. As a result, infant sign training may result in better speech-language skills compared with the control interventions. What are the potential or actual clinical implications of this work? If providing early intervention based on infant sign training is effective, there is the potential for improved speech-language outcomes in early childhood, resulting in increased speech intelligibility, increased well-being of the child and family and less need for speech-language therapy on the long-term. This project will contribute to the development of evidence-based clinical practice guidelines regarding early speech-language intervention in children with CP ± L under the age of 3 years.

Preserving Inhibition during Developmental Hearing Loss Rescues Auditory Learning and Perception

Transient periods of childhood hearing loss can induce deficits in aural communication that persist long after auditory thresholds have returned to normal, reflecting long-lasting impairments to the auditory CNS. Here, we asked whether these behavioral deficits could be reversed by treating one of the central impairments: reduction of inhibitory strength. Male and female gerbils received bilateral earplugs to induce a mild, reversible hearing loss during the critical period of auditory cortex development. After earplug removal and the return of normal auditory thresholds, we trained and tested animals on an amplitude modulation detection task. Transient developmental hearing loss induced both learning and perceptual deficits, which were entirely corrected by treatment with a selective GABA reuptake inhibitor (SGRI). To explore the mechanistic basis for these behavioral findings, we recorded the amplitudes of GABA_A and GABA_B receptor-mediated IPSPs in auditory cortical and thalamic brain slices. In hearing loss-reared animals, cortical IPSP amplitudes were significantly reduced within a few days of hearing loss onset, and this reduction persisted into adulthood. SGRI treatment during the critical period prevented the hearing loss-induced reduction of IPSP amplitudes; but when administered after the critical period, it only restored GABA_B receptor-mediated IPSP amplitudes. These effects were driven, in part, by the ability of SGRI to upregulate α1 subunit-dependent GABA_A responses. Similarly, SGRI prevented the hearing loss-induced reduction of GABA_A and GABA_B IPSPs in the ventral nucleus of the medial geniculate body. Thus, by maintaining, or subsequently rescuing, GABAergic transmission in the central auditory thalamocortical pathway, some perceptual and cognitive deficits induced by developmental hearing loss can be prevented.SIGNIFICANCE STATEMENT Even a temporary period of childhood hearing loss can induce communication deficits that persist long after auditory thresholds return to normal. These deficits may arise from long-lasting central impairments, including the loss of synaptic inhibition. Here, we asked whether hearing loss-induced behavioral deficits could be reversed by reinstating normal inhibitory strength. Gerbils reared with transient hearing loss displayed both learning and perceptual deficits. However, when animals were treated with a selective GABA reuptake inhibitor during or after hearing loss, behavioral deficits were entirely corrected. This behavioral recovery was correlated with the return of normal thalamic and cortical inhibitory function. Thus, some perceptual and cognitive deficits induced by developmental hearing loss were prevented with a treatment that rescues a central synaptic property.

Current evidence of peripheral vestibular symptoms secondary to otitis media

BACKGROUND

The association between otitis media and vestibular symptoms has been hypothesized in the past. Thus, in this study, we aimed to critically analyze (based in a systematic review of the literature) whether patients who have otitis media are at greater risk of developing vestibular impairment or not.

METHODS

We performed a systematic review of the literature and identified potentially relevant articles reporting vestibular symptoms and results of vestibular function tests in patients with otitis media through searches of the PubMED, Web of Science, Scopus, and Google Scholar databases. The quality of the final set of records was assessed using the "Newcaste-Ottawa Scale".

RESULTS

Of the 2334 records searched, 43 met our inclusion and exclusion criteria, and those included 2250 patients. The records comprised 20 longitudinal studies, 21 cross-sectional studies, and 2 case reports. Regarding the type of otitis media studied, 25 examined vestibular impairment in otitis media with effusion, 6 acute otitis media, and 12 chronic otitis media. Results of anamnesis, clinical exams, and several vestibular function tests are reported and critically discussed.

CONCLUSION

Most studies evaluating the association between otitis media and vestibular symptoms have potential methodological flaws. Clinical evidence suggests that patients with otitis media have increased chances for having vestibular symptoms, delayed acquisition of developmental milestones, and abnormalities in several vestibular function tests as compared with controls. Future studies with rigorous methodology aiming to assess the clinical significance (and prognostic factors) of the association between otitis media and vestibular impairment are warranted. Key message Several studies demonstrated long-term sequelae secondary to otitis media. However, the evidence supporting those assumptions are based in low-quality evidence. Thus, better structured studies are warranted to better understand the clinical relevance of such association.

Long-term influence of recurrent acute otitis media on neural involuntary attention switching in 2-year-old children

BACKGROUND

A large group of young children are exposed to repetitive middle ear infections but the effects of the fluctuating hearing sensations on immature central auditory system are not fully understood. The present study investigated the consequences of early childhood recurrent acute otitis media (RAOM) on involuntary auditory attention switching.

METHODS

By utilizing auditory event-related potentials, neural mechanisms of involuntary attention were studied in 22-26 month-old children (N = 18) who had had an early childhood RAOM and healthy controls (N = 19). The earlier and later phase of the P3a (eP3a and lP3a) and the late negativity (LN) were measured for embedded novel sounds in the passive multi-feature paradigm with repeating standard and deviant syllable stimuli. The children with RAOM had tympanostomy tubes inserted and all the children in both study groups had to have clinically healthy ears at the time of the measurement assessed by an otolaryngologist.

RESULTS

The results showed that lP3a amplitude diminished less from frontal to central and parietal areas in the children with RAOM than the controls. This might reflect an immature control of involuntary attention switch. Furthermore, the LN latency was longer in children with RAOM than in the controls, which suggests delayed reorientation of attention in RAOM.

CONCLUSIONS

The lP3a and LN responses are affected in toddlers who have had a RAOM even when their ears are healthy. This suggests detrimental long-term effects of RAOM on the neural mechanisms of involuntary attention.

Auditory temporal abilities in children with history of recurrent otitis media in the first years of life and persistent in preschool and school ages

PURPOSE

To study the temporal auditory ordering and resolution abilities in children with and without a history of early OME and ROME, as well as to study the responses according to age.

METHODS

A total of 59 children were evaluated, and all of them presented pure tone thresholds within the normal range at the time of the conduction of the hearing tests. The children were divided into two groups according to the occurrence of episodes of recurrent otitis media. Then, each group was divided into two subgroups according to age: 7- and 8-year olds, and 9- and 10-year olds. All children were assessed with standard tests of temporal frequency (ordination) and gaps-in-noise (resolution).

RESULTS

For the temporal abilities studied, children with a history of otitis media presented significantly lower results compared to the control group. In the frequency pattern test, the correct answers increased with age in both groups. In the identification of silence intervals, the control group showed no change in threshold regarding to age, but this change was present in the group with a history of otitis media.

CONCLUSION

Episodes of otitis media with effusion in the first year of life, recurrent and persistent in preschool and school ages, negatively influence the temporal ordering and resolution abilities.

Switch attention to listen

The aim of this research was to evaluate the ability to switch attention and selectively attend to relevant information in children (10-15 years) with persistent listening difficulties in noisy environments. A wide battery of clinical tests indicated that children with complaints of listening difficulties had otherwise normal hearing sensitivity and auditory processing skills. Here we show that these children are markedly slower to switch their attention compared to their age-matched peers. The results suggest poor attention switching, lack of response inhibition and/or poor listening effort consistent with a predominantly top-down (central) information processing deficit. A deficit in the ability to switch attention across talkers would provide the basis for this otherwise hidden listening disability, especially in noisy environments involving multiple talkers such as classrooms.