Auditory Perceptual Problems in Children: Considerations for the Otolaryngologist and Audiologist

Five cases of children with auditory processing problems are presented. These children had essentially normal peripheral hearing and ENT exam, but were referred with a question of hearing loss. An auditory perceptual test battery including rapidly alternating speech (RASP), binaural fusion, low pass filtered speech (LPFS), competing sentences, staggered spondiac words (SSW), dichotic digits and frequency patterns was employed. Though some of these tests did not show a perceptual deficit, the majority did depict specific types of auditory processing problems. Based on the information provided by this test battery, appropriate diagnosis and therapy can be provided for the patient.     

Speech perception in noise for children with auditory neuropathy/dys-synchrony type hearing loss

OBJECTIVE: To evaluate the effect of background noise on speech perception in children with auditory neuropathy/dys-synchrony (AN/AD) type hearing loss. DESIGN: Open and closed-set speech perception abilities were assessed in 12 school-age children who had been diagnosed with AN/AD in infancy. Data were also obtained from a cohort of subjects with sensorineural (SN) hearing loss and from a group of normal-hearing children. RESULTS: Closed-set speech understanding was more affected by the presence of a competing signal in the hearing impaired than in the normal-hearing subjects. The mean S/N ratio required to identify a spondee in noise was -11.5 +/- 2.0 dB for the normal group, whereas the ratio required for the SN group was -5.4 +/- 5.1 dB and for the AN/AD group was -2.5 +/- 4.7 dB. Closed-set perception in noise was not significantly different for the AN/AD children and their SN counterparts although there was a trend toward poorer performance in the AN/AD group. The effect of background noise on open-set speech perception was also similar across hearing-impaired subjects although again, the AN/AD cohort tended to show greater difficulties in noise than their SN peers. CONCLUSIONS: Listening in background noise was more difficult for our group of children with AN/AD-type hearing loss than for their normal-hearing peers. However, the noise effects were not consistent across subjects and some children demonstrated reasonable perceptual ability at low signal-to-noise ratios. The ways in which speech understanding is affected by competing signals may be different for different types of hearing deficit, but the results of this investigation indicate that significant perceptual disruption occurs both in children with auditory neuropathy/dys-synchrony and sensorineural type hearing loss.     

Perceptual characterization of children with auditory neuropathy

OBJECTIVE: To characterize the perceptual abilities of a group of children with auditory neuropathy (AN)-type hearing loss, correlating results on a range of psychophysical tasks with open-set speech perception performance. DESIGN: Frequency resolution, temporal resolution and frequency discrimination ability was assessed in a group of 14 children with AN. Data also were obtained from a cohort of matched subjects with sensorineural hearing loss, and from a group of normally hearing children. RESULTS: Frequency resolution (notched noise masking) results for the AN subjects were equivalent to those of the normal-hearing subjects reflecting the "normal" outer hair cell function that characterizes the AN condition. Temporal resolution (TMTF) findings were, however, abnormal in many AN subjects and the degree of temporal disruption was correlated with speech discrimination (CNC) score. Frequency discrimination ability (for both fixed and frequency modulated stimuli) was also affected in those children with poor temporal resolution. CONCLUSIONS: The findings of this study indicate that the perceptual profiles of children with AN are quite different from those with sensorineural hearing loss. Where subjects in the latter group presented with impaired frequency resolution and normal temporal processing, the AN subjects typically showed normal frequency resolution and varying degrees of temporal disruption. The severity of this temporal abnormality, which appeared to affect both temporal resolution/amplitude modulation detection and the temporal aspects of frequency discrimination (such as phase locking), was strongly correlated to speech perception performance.     

Auditory pathway encoding and neural plasticity in children with learning problems.

An inability to process auditory information, especially speech, characterizes many children with learning and attention problems. Our working hypothesis is that these speech-sound perception problems arise, at least in some cases, from faulty representation of the speech signal in central auditory centers. Preconscious neurophysiologic representation of sound structure by central auditory pathway neurons can be reflected by subcortical and cortical aggregate neural responses. These neurophysiologic responses can be modified by perceptual learning. Our research has shown that some children with learning problems demonstrate abnormal perception and neural representation of certain speech sounds. Differences between normal and learning-impaired groups can be attributable to aspects of neural synchrony that are reflected in aggregate neural responses. Deficiencies in neural synchrony in these children are apparent in subcortical (as well as cortical) representations of speech-sound structure, and these timing deficits are related to performance on speech-sound perception and learning measures. Moreover, impaired perception and neurophysiologic encoding of speech sounds can be improved with cue enhancement and can be modified by perceptual learning associated with auditory training.     

Auditory brainstem response,middle latency response,and late cortical evoked potentials in children with learning disabilities

Auditory evoked potentials (AEPs) and behavioral tests were used to evaluate auditory processing in 10 children aged 7 to 11 years who were diagnosed as learning disabled (LD). AEPs included auditory brainstem responses (ABRs), middle latency responses (MLRs), and late cortical responses (P1, N1, P2, P3). Late cortical responses were recorded using an active listening oddball procedure. Auditory processing disorders were suspected in the LD children after a psychologist found phonologic processing and auditory memory problems. A control group of 10 age- and gender-matched children with no hearing or reported learning difficulties was also tested. Teacher ratings of classroom listening and SCAN Competing Words and Staggered Spondaic Word scores were poorer in the LD children. There were minor ABR latency differences between the two groups. Wave Na of the MLR was later and Nb was smaller in the LD group. The main differences in cortical responses were that P1 was earlier and P3 was later and smaller in the LD group.     

Distinguishing auditory and speech-specific perceptual deficits

The ability to discriminate speech and nonspeech auditory stimuli was tested in a learning disabled child. The perception of speech stimuli was normal when the stimuli were presented in quiet but below normal when the stimuli were presented in noise. Although the perception of pure tone stimuli and environmental sounds was normal both in quiet and noise, the perception of nonspeech stimuli with rapid changes in acoustic information was impaired in noise. These findings illustrate the importance of relating performance for speech and complex nonspeech stimuli in investigating the basis of speech perceptual deficits. Whereas abnormal performance for speech stimuli coupled with normal performance for complex nonspeech stimuli argues for the existence of specialized speech processing mechanisms, abnormal performance for both types of stimuli, as was found in the present subject, argues for the existence of more generalized auditory processing mechanisms.     

Auditory performance and speech intelligibility of Mandarin-speaking children implanted before age 5

Objectives

(1) To report the auditory performance and speech intelligibility of 84 Mandarin-speaking prelingually deaf children after using cochlear implants (CIs) for one, two, three, four, and five years to understand how many years of implant use were needed for them to reach a plateau-level performance; (2) to investigate the relation between subjective rating scales and objective measurements (i.e., speech perception tests); (3) to understand the effect of age at implantation on auditory and speech development.

Methods

Eighty-four children with CIs participated in this study. Their auditory performance and speech intelligibility were rated using the Categorical Auditory Performance (CAP) and the Speech Intelligibility Rating (SIR) scales, respectively. The evaluations were made before implantation and six months, one, two, three, four, and five years after implantation. At the fifth year after implantation, monosyllabic-word, easy-sentence, and difficult-sentence perception tests were administered.

Results

The median CAP score reached a plateau at category 6 after three years of implant use. The median SIR arrived at the highest level after five years of use. With five years of CI experiences, 86% of the subjects understood conversation without lip-reading, and 58% were fully intelligible to all listeners. The three speech perception tests had a moderate-to-strong correlation with the CAP and SIR scores. The children implanted before the age of three years had significantly better CAP and monosyllabic word perception test scores.

Conclusions

Five years of follow-up are needed for assessing the post-implantation development of communication ability of prelingually deafened children. It is recommended that hearing-impaired children receive cochlear implantation at a younger age to acquire better auditory ability for developing language skills. Constant postoperative aural–verbal rehabilitation and speech and language therapy are most likely required for the patients to reach the highest level on the CAP and SIR scales.     

Brainstem timing deficits in children with learning impairment may result from corticofugal origins

A substantial proportion of children with language-based learning problems [learning disabilities (LD)] display abnormal encoding of speech at rostral levels of the auditory brainstem (i.e. midbrain) as measured by the auditory brainstem response (ABR). Of interest here is whether these timing deficits originate at the rostral brainstem or whether they reflect deficient sensory encoding at lower levels of the auditory pathway. We describe the early brainstem response to speech (waves I and III) in typically developing 8- to 12-year-old children and children with LD. We then focus on the early brainstem responses in children with LD found to show abnormal components of the rostral speech-evoked ABR (waves V and A). We found that wave I was not reliably evoked using our speech stimulus and recording parameters in either typically developing children or those with LD. Wave III was reliably evoked in the large majority of subjects in both groups and its timing did not differ between them. These data are consistent with the view that the auditory deficits in the majority of LD children with abnormal speech-evoked ABR originate from corticofugal modulation of subcortical activity.     

Word identification performance in the presence of competing speech and noise in learning disabled adults

Eight learning disabled (LD) adults and eight control subjects identified monosyllabic words presented simultaneously in the presence of speech spectrum noise and three types of linguistic maskers. The performance of LD subjects was poorer than that of the control subjects under each masking condition. Word identification was poorest in the presence of speech noise for both groups. No difference in performance was seen as a function of the linguistic content of the competing speech maskers. These results suggest that LD subjects present greater susceptibility to acoustic masking relative to control subjects and may support the view that auditory-language deficits observed in LD individuals may be secondary to an underlying acoustic-phonetic disorder rather than a central phonologic disorder. LD college students may experience S/N ratios in the classroom that perpetuate or exacerbate their listening problems.     

The effects of time compression on the auditory processing abilities of learning disabled children

This study measured the ability of ten 8- and ten 12-yr-old learning disabled (LD) children of normal intelligence (WISC-R) to discriminate phonemic contrasts in sentential stimuli (Subtest 13 of the Carrow Auditory Visual Abilities Test) presented at a 50% time-compression rate. Their group responses were compared statistically to similar data gathered earlier (May et al, J. Aud. Res., 1984, 24, 205-211) from 6-, 8-, and 10-yr-old normal children and young adults. LD Ss exhibited auditory processing capacities reminiscent of an earlier level of operation (e.g., the group of LD Ss with mn age of 12.8 yrs yielded group performance equivalent to that of normal 6- and 8-yr-olds), and also manifested marked differences in their feature- and frequency-processing abilities. These data indicate that contributing to the learning difficulties of LD children may very well be delays in auditory development and anomalies in auditory-feature processing.     

Auditory and cognitive abilities of children suspected of auditory processing disorder (APD)

Objective

Auditory processing disorder (APD) is typically characterised by difficulties in ‘listening’, particularly to speech in a noisy environment, despite normal peripheral function. In school-age children, APD has attracted considerable interest because of suspicions that it may lead to learning difficulties, especially affecting language and literacy. Here, we evaluated auditory and cognitive abilities in a group of children referred for an auditory evaluation on the grounds of a suspected auditory processing disorder (susAPD), and in age-matched children who were typically developing, in order to determine the extent to which any deficits in cognitive abilities could be related to auditory deficits.

Methods

A battery of auditory and cognitive tests was applied to 20 susAPD school-age children, all reported as having listening/hearing problems but performing within normal limits for standard audiometric assessments. Also tested was a group of 28 age-matched controls. The auditory tasks consisted of two simple same/different discrimination tasks, one using speech, and one nonspeech. The cognitive evaluation comprised a vocabulary test, a test of grammar and four non-verbal IQ measures. Symptoms of Attention Deficit Hyperactivity Disorder (ADHD) were assessed in the susAPD group through a standardised questionnaire.

Results

A significant proportion of susAPD children appeared to display genuine auditory deficits evidenced by poor performance on at least one of the auditory tasks, although about 1/3 had no detectable deficit. Children in the susAPD group scored consistently lower than the controls on cognitive measures that were both verbal (vocabulary and grammar) and non-verbal. Strikingly, susAPD children with relatively good auditory performance did not differ in cognitive ability from susAPD children with poor auditory performance. Similarly, within-group correlations between auditory and cognitive measures were weak or non-existent. Measures of ADHD did not correlate with any aspect of auditory or cognitive performance.

Conclusions

Although children suspected of having APD do show, on average, poorer performance on a number of auditory tasks, the presence or absence of an auditory deficit appears to have little impact on the development of the verbal and non-verbal skills tested here.     

Effect of age at cochlear implantation on auditory and speech development of children with auditory neuropathy spectrum disorder

Objective

To evaluate the auditory and speech abilities in children with auditory neuropathy spectrum disorder (ANSD) after cochlear implantation (CI) and determine the role of age at implantation.

Methods

Ten children participated in this retrospective case series study. All children had evidence of ANSD. All subjects had no cochlear nerve deficiency on magnetic resonance imaging and had used the cochlear implants for a period of 12–84 months. We divided our children into two groups: children who underwent implantation before 24 months of age and children who underwent implantation after 24 months of age. Their auditory and speech abilities were evaluated using the following: behavioral audiometry, the Categories of Auditory Performance (CAP), the Meaningful Auditory Integration Scale (MAIS), the Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS), the Standard-Chinese version of the Monosyllabic Lexical Neighborhood Test (LNT), the Multisyllabic Lexical Neighborhood Test (MLNT), the Speech Intelligibility Rating (SIR) and the Meaningful Use of Speech Scale (MUSS).

Results

All children showed progress in their auditory and language abilities. The 4-frequency average hearing level (HL) (500 Hz, 1000 Hz, 2000 Hz and 4000 Hz) of aided hearing thresholds ranged from 17.5 to 57.5 dB HL. All children developed time-related auditory perception and speech skills. Scores of children with ANSD who received cochlear implants before 24 months tended to be better than those of children who received cochlear implants after 24 months. Seven children completed the Mandarin Lexical Neighborhood Test. Approximately half of the children showed improved open-set speech recognition.

Conclusion

Cochlear implantation is helpful for children with ANSD and may be a good optional treatment for many ANSD children. In addition, children with ANSD fitted with cochlear implants before 24 months tended to acquire auditory and speech skills better than children fitted with cochlear implants after 24 months.     

Comparison between Central Tonal Tests and Central Speech Tests in Elderly Subjects

A battery of tonal tests investigating the performance of the central auditory pathways (auditory lateralization, temporal order, auditory pattern) has been applied, together with a battery of central speech tests (sensitized speech and synthetic sentences), to a group of 50 subjects aged from 60 to 80 years, affected only with presbyacusis. The results demonstrate that the speech tests undergo a considerable reduction of the performance-intensity function with age whereas the tonal tests remain within the values obtained in younger subjects. The topodiagnostic implications of these data are discussed.     

Sprachverständnis im Störgeräusch mit und ohne Frequenzmodulationsanlage

Background

In the presence of a (central) auditory processing disorder [(C)APD] central hearing processes are disturbed, leading to impaired speech perception in noise. Poor acoustics in educational institutions exacerbates the problem. In children affected by (C)APD this can result in impaired development of language, reading and writing acquisition as well as other skills.

Materials and methods

A total of 66 children aged 6–11 years completed the Oldenburg sentence test in noise (OlSa) with and without an FM system. Children with normal OlSa test results formed the control group (group 1), while group 2a comprised children with an unremarkable re-test result and group 2b comprised children who produced abnormal results even in the re-test.

Results

All children achieved improved speech intelligibility using the FM system. The greatest difference between results with and without FM system was seen in group 2b (9.53 dB S/N). Group 1 achieved an improvement of 8.86 dB S/N and group 2a 7.89 dB S/N.

Conclusions

Children with detected auditory selection problems benefit most from the use of an FM system for improved speech understanding. This should be borne in mind in the diagnosis and therapy of these children.     

A critical examination of vestibular function in motor-impaired learning-disabled children

This study examined the role of the vestibular system in balance and coordination problems found in motor-impaired, learning-disabled (LD) children. Vestibulo-ocular reflex (VOR) and vestibulo-spinal tests (moving platform posturography) were performed on 15 learning disabled and 54 normal children. Twelve LD children had normal VOR scores suggesting normal peripheral vestibular inputs. All 15 LD children had abnormal posturography. Motor-impaired LD children could not appropriately integrate vestibular information with visual and somatosensory inputs for postural orientation. Results suggest that the best discriminator of abnormal sensorimotor function in LD children are posturography trials requiring orientation to gravity despite absent or inaccurate visual and somatosensory cues, rather than traditionally relied on VOR and Romberg tests.     

Auditory-visual speech integration by adults with and without language-learning disabilities

Auditory and auditory-visual (AV) speech perception skills were examined in adults with and without language-learning disabilities (LLD). The AV stimuli consisted of congruent consonant-vowel syllables (auditory and visual syllables matched in terms of syllable being produced) and incongruent McGurk syllables (auditory syllable differed from visual syllable). Although the identification of the auditory and congruent AV syllables was comparable for the two groups, the reaction times to identify all syllables were longer in the LLD compared to the control group. This finding is consistent with previous research demonstrating slower processing in learning disabled individuals. Adults with LLD also provided significantly fewer integration-type or McGurk responses compared with their normal peers when presented with speech tokens representing a mismatch between the auditory and visual signal. These results suggest the poor integration for auditory-visual speech previously documented in children with poor language skills also occurs in adults with LLD. LEARNING OUTCOMES: The reader will be able to (1) describe the McGurk effect; (2) describe group differences (language learning disabled and control adults) in auditory and auditory-visual speech perception of consonant-vowel syllables.     

Auditory processing disorders: Relationship to cognitive processes and underlying auditory neural integrity

Background

Auditory processing disorder (APD) in children has been reported and discussed in the clinical and research literature for many years yet there remains poor agreement on diagnostic criteria, the relationship between APD and cognitive skills, and the importance of assessing underlying neural integrity.

Purpose

The present study used a repeated measures design to examine the relationship between a clinical APD diagnosis achieved with behavioral tests used in many clinics, cognitive abilities measured with standardized tests of intelligence, academic achievement, language, phonology, memory and attention and measures of auditory neural integrity as measured with acoustic reflex thresholds and auditory brainstem responses.

Method

Participants were 63 children, 7–17 years of age, who reported listening difficulties in spite of normal hearing thresholds. Parents/guardians completed surveys about the child's auditory and attention behavior while children completed an audiologic examination that included 5 behavioral tests of auditory processing ability. Standardized tests that examined intelligence, academic achievement, language, phonology, memory and attention, and objective tests auditory function included crossed and uncrossed acoustic reflex thresholds and auditory brainstem responses (ABR) were also administered to each child.

Results

Forty of the children received an APD diagnosis based on the 5 behavioral tests and 23 did not. The groups of children performed similarly on intelligence measures but the children with an APD diagnosis tended to perform more poorly on other cognitive measures. Auditory brainstem responses and acoustic reflex thresholds were often abnormal in both groups of children.

Summary

Results of this study suggest that a purely behavioral test battery may be insufficient to accurately identify all children with auditory processing disorders. Physiologic test measures, including acoustic reflex and auditory brainstem response tests, are important indicators of auditory function and may be the only indication of a problem. The results also suggest that performance on behavioral APD tests may be strongly influenced by the child's language levels.