Speech Perception Skills Research Articles

Speech Perception in Congenitally Deaf Children Receiving Cochlear Implants in the First Year of Life

To investigate whether children implanted in the first year of life show higher levels of speech perception than later-implanted children, when compared at the same ages and to investigate the time course of sensitive periods for developing speech perception skills. More specifically, to determine whether faster gains in speech perception are made by children implanted before 1 year old relative to those implanted at 2 or 3 years. Retrospective cohort study. Tertiary academic referral center. 117 children with congenital profound bilateral sensorineural hearing loss, with no additional identified disabilities. Cochlear implantation in the first, second, or third year of life. Development curves showing Lexical Neighborhood Test (LNT) word identification scores as a function of age. Children implanted within the first year of life have a mean advantage of 8.2% LNT-easy word scores over those implanted in the second year (p < 0.001) and a 16.8% advantage in LNT-easy word scores over those implanted in the third year of life (p < 0.001). These advantages remained statistically significant after accounting for sex, residual hearing, and bilateral cochlear implant use. When speech perception scores were expressed as a function of "hearing age" rather than chronological age, however, there were no significant differences among the 3 groups. There is a clear speech perception advantage for earlier-implanted children over later-implanted children when compared at the same age but not when compared at the same time after implantation. Thus, the sensitive period for developing word identification seems to extend at least until age 3 years.

Cochlear Implant Characteristics and Speech Perception Skills of Adolescents With Long-Term Device Use

Updated cochlear implant technology and optimized fitting can have a substantial impact on speech perception. The effects of upgrades in processor technology and aided thresholds on word recognition at soft input levels and sentence recognition in noise were examined. We hypothesized that updated speech processors and lower aided thresholds would allow improved recognition of soft speech without compromising performance in noise. 109 teenagers who had used a Nucleus 22-cochlear implant since preschool were tested with their current speech processor(s) (101 unilateral and 8 bilateral): 13 used the Spectra, 22 the ESPrit 22, 61 the ESPrit 3G, and 13 the Freedom. The Lexical Neighborhood Test (LNT) was administered at 70 and 50 dB SPL and the Bamford Kowal Bench sentences were administered in quiet and in noise. Aided thresholds were obtained for frequency-modulated tones from 250 to 4,000 Hz. Results were analyzed using repeated measures analysis of variance. Aided thresholds for the Freedom/3G group were significantly lower (better) than the Spectra/Sprint group. LNT scores at 50 dB were significantly higher for the Freedom/3G group. No significant differences between the 2 groups were found for the LNT at 70 or sentences in quiet or noise. Adolescents using updated processors that allowed for aided detection thresholds of 30 dB HL or better performed the best at soft levels. The BKB in noise results suggest that greater access to soft speech does not compromise listening in noise.

Communication, Listening, Cognitive and Speech Perception Skills in Children With Auditory Processing Disorder (APD) or Specific Language Impairment (SLI)

Parental reports of communication, listening, and behavior in children receiving a clinical diagnosis of specific language impairment (SLI) or auditory processing disorder (APD) were compared with direct tests of intelligence, memory, language, phonology, literacy, and speech intelligibility. The primary aim was to identify whether there were differences between these characteristics in children with SLI or APD. Normally hearing children who were clinically diagnosed with SLI (n = 22) or APD (n = 19), and a quasirandom sample of mainstream school (MS) children (n = 47) aged 6-13 years, underwent tests of verbal and nonverbal IQ, digit span, nonsense word repetition, Spoonerisms, reading, grammar, and sentence and VCV nonword intelligibility. Parents completed questionnaires on the children's communication, listening, and behavior. There was generally no difference between the performance of the children with SLI and the children with APD on the questionnaire and test measures, and both groups consistently and significantly underperformed compared with the children in the MS group. Speech intelligibility in both noise and quiet was unimpaired in the SLI and APD groups. Despite clinical diagnoses of SLI or APD, the 2 groups of children had very similar behavioral and parental report profiles, suggesting that the children were differentially diagnosed based on their referral route rather than on actual differences.

Cochlear Implantation in Children with Auditory Neuropathy Spectrum Disorder

To report the patient's characteristics, preoperative audiological profiles, surgical outcomes, and postoperative performance for children with auditory neuropathy spectrum disorder (ANSD) who ultimately received cochlear implants (CIs). Prospective, longitudinal study of children with ANSD who received CIs after a stepwise management protocol that included electrophysiologic and medical assessment, documentation of behavioral audiometric thresholds and subsequent fitting of amplification according to Desired Sensation Level targets, auditory-based intervention with careful monitoring of skills development and communication milestones, and finally implantation when progress with the use of acoustic amplification was insufficient. Of 140 children with ANSD, 52 (37%) received CIs in their affected ears (mean duration of use of 41 mos). Many of these children were born prematurely (42%) and impacted by a variety of medical comorbidities. More than one third (38%) had abnormal findings on preoperative magnetic resonance imaging of the brain and inner ear, and 81% had a greater than severe (>70 dB HL) degree of hearing loss before implantation. Although 50% of the implanted children with ANSD demonstrated open-set speech perception abilities after implantation, nearly 30% of them with >6 months of implant experience were unable to participate in this type of testing because of their young age or developmental delays. No child with cochlear nerve deficiency (CND) in their implanted ear achieved open-set speech perception abilities. In a subgroup of children, good open-set speech perception skills were associated with robust responses elicited on electrical-evoked intracochlear compound action potential testing when this assessment was possible. This report shows that children with ANSD who receive CIs are a heterogeneous group with a wide variety of impairments. Although many of these children may ultimately benefit from implantation, some will not, presumably because of a lack of electrical-induced neural synchronization, the detrimental effects of their other associated conditions, or a combination of factors. When preoperative magnetic resonance imaging reveals central nervous system pathology, this portends a poor prognosis for the development of open-set speech perception, particularly when CND is evident. These results also show that electrical-evoked intracochlear compound action potential testing may help identify those children who will develop good open-set speech perception. Instead of recommending CI for all children with electrophysiologic evidence of ANSD, the stepwise management procedure described herein allows for the identification of children who may benefit from amplification, those who are appropriate candidates for cochlear implantation, and those who, because of bilateral CND, may not be appropriate candidates for either intervention.

Inferior Frontal Gyrus Activation Predicts Individual Differences in Perceptual Learning of Cochlear-Implant Simulations

This study investigated the neural plasticity associated with perceptual learning of a cochlear implant (CI) simulation. Normal-hearing listeners were trained with vocoded and spectrally shifted speech simulating a CI while cortical responses were measured with functional magnetic resonance imaging (fMRI). A condition in which the vocoded speech was spectrally inverted provided a control for learnability and adaptation. Behavioral measures showed considerable individual variability both in the ability to learn to understand the degraded speech, and in phonological working memory capacity. Neurally, left-lateralized regions in superior temporal sulcus and inferior frontal gyrus (IFG) were sensitive to the learnability of the simulations, but only the activity in prefrontal cortex correlated with interindividual variation in intelligibility scores and phonological working memory. A region in left angular gyrus (AG) showed an activation pattern that reflected learning over the course of the experiment, and covariation of activity in AG and IFG was modulated by the learnability of the stimuli. These results suggest that variation in listeners' ability to adjust to vocoded and spectrally shifted speech is partly reflected in differences in the recruitment of higher-level language processes in prefrontal cortex, and that this variability may further depend on functional links between the left inferior frontal gyrus and angular gyrus. Differences in the engagement of left inferior prefrontal cortex, and its covariation with posterior parietal areas, may thus underlie some of the variation in speech perception skills that have been observed in clinical populations of CI users.

Speech perception performance for 100 post-lingually deaf adults fitted with Neurelec cochlear implants: Comparison between Digisonic® Convex and Digisonic® SP devices after a 1-year follow-up

Conclusion: Patients implanted with the Digisonic® SP device showed better identification scores than those implanted with the Convex device, with skills continuing to improve over a longer time period. Technological improvements were beneficial in terms of speech perception in quiet. Objective: To compare speech perception skills for post-lingually deaf patients implanted with a previous Neurelec device, the Digisonic® Convex, with those implanted with a more recent one, the Digisonic® SP, which provides more electrodes and a faster stimulation rate. Methods: This was a retrospective study of 100 implanted patients, 45 with the Digisonic® Convex implant and 55 with the Digisonic® SP. Speech perception (dissyllabic words and sentences, in open set) was evaluated until 1 year after implantation. Results: Patients fitted with the Digisonic® SP implant showed significantly better scores after 3, 6, and 12 months (mean scores: 53%, 62%, and 68% for words; 58%, 69%, and 75% for sentences) than those fitted with the Convex implant (34%, 42%, and 43% for words; 38%, 59%, and 51% for sentences). The improvement in speech perception after implantation for SP patients continued throughout the 12 months for words and 6 months for sentences, versus 6 months for words and 3 months for sentences for Convex patients.

Logatome Discrimination in Cochlear Implant Users: Subjective Tests Compared to the Mismatch Negativity

This paper describes a logatome discrimination test for the assessment of speech perception in cochlear implant users (CI users), based on a multilingual speech database, the Oldenburg Logatome Corpus, which was originally recorded for the comparison of human and automated speech recognition. The logatome discrimination task is based on the presentation of 100 logatome pairs (i.e., nonsense syllables) with balanced representations of alternating “vowel-replacement” and “consonant-replacement” paradigms in order to assess phoneme confusions. Thirteen adult normal hearing listeners and eight adult CI users, including both good and poor performers, were included in the study and completed the test after their speech intelligibility abilities were evaluated with an established sentence test in noise. Furthermore, the discrimination abilities were measured electrophysiologically by recording the mismatch negativity (MMN) as a component of auditory event-related potentials. The results show a clear MMN response only for normal hearing listeners and CI users with good performance, correlating with their logatome discrimination abilities. Higher discrimination scores for vowel-replacement paradigms than for the consonant-replacement paradigms were found. We conclude that the logatome discrimination test is well suited to monitor the speech perception skills of CI users. Due to the large number of available spoken logatome items, the Oldenburg Logatome Corpus appears to provide a useful and powerful basis for further development of speech perception tests for CI users.

Speech Perception Among School-Aged Skilled and Less Skilled Readers

This study investigated the relationship between speech perception, phonological processing and reading skills among school-aged children classified as 'skilled' and 'less skilled' readers based on their ability to read words, decode non-words, and comprehend short passages. Three speech perception tasks involving categorization of speech continua differing in voicing, place and manner of articulation were administered and compared to phonological processing skills in phonological awareness, speeded naming and verbal short-term memory. The results obtained suggested that (a) speech categorization among skilled readers differed from that of less skilled readers, (b) speech perception skills were associated with both reading and phonological processing skills among both skilled and less skilled readers, however, (c) a strong association between speeded naming and both word and passage reading skills found among skilled readers was absent among less skilled readers. These results suggested that phonological representations and/or activation may not be as well developed in less skilled readers.

Longitudinal Study of Speech Perception, Speech, and Language for Children with Hearing Loss in an Auditory-Verbal Therapy Program

This study examined the speech perception, speech, and language developmental progress of 25 children with hearing loss (mean Pure-Tone Average [PTA] 79.37 dB HL) in an auditory-verbal therapy program. Children were tested initially and then 21 months later on a battery of assessments. The speech and language results over time were compared with those for a control group of children with typical hearing who were matched for initial language age, receptive vocabulary, gender, and socioeconomic level. Speech perception scores for the children with hearing loss showed significant improvement (p 0.05). At the 21-month test point, 84% of the children with hearing loss scored within the typical range for total language age, compared to 58.6% at the initial assessment. Receptive vocabulary scores were an exception, with the children with typical hearing showing significantly more gain than the children with hearing loss (p < 0.05). Nevertheless, the group with hearing loss scored within the typical range for receptive vocabulary. Overall, the results show that the children with hearing loss had improved speech perception skills over time and that their rate of progress for speech and language skills was similar to that of children with typical hearing.

Evolution of Cochlear Implant Arrays Result in Changes in Behavioral and Physiological Responses in Children

To determine whether a change in cochlear implant technology and electrode array design affects electrophysiological, behavioral, and functional measures of audition in pediatric cochlear implant users. Prospective nonrandomized control study over 6 months postimplantation. Tertiary referral pediatric hospital. A total of 115 children using unilateral cochlear implants were included in this study. Subjects were divided into 3 groups: 1) 38 using the Nucleus 24M straight array device, 2) 20 using the perimodiolar Nucleus 24RCS Contour array, and 3) 57 using the perimodiolar Nucleus 24RE array with advance off stylet insertion. The mean ages at implantation were 4.85 +/- 4 (24M), 3.88 +/- 3.4 (24RCS), and 5.41 +/- 4.36 years (24RE; not significant, p > 0.05). The electrically evoked compound action potential (ECAP) and the electrically evoked stapedius reflex and behavioral measures of stimulation threshold were evoked by stimulation of basal, mid, and apical electrodes. These measures were completed at regular intervals over 6 to 12 months of implantation. Age-appropriate speech perception skills were also assessed during this period. The 24RE array group had significantly lower ECAP and behavioral thresholds compared with the 24M and 24RCS array groups. The largest reductions of ECAP thresholds in the precurved array group were observed upon apical and basal electrode stimulation. Electrically evoked stapedius reflex thresholds were significantly higher in the 24RE group as compared with 24M and 24RCS groups. Comparing age-matched groups, open- and closed-set speech perception test scores were significantly higher in the 24RE array group. The precurved Freedom 24RE cochlear implant potentially provides a wider range of stimulation levels and better functional results than the straight electrode 24M and the precurved 24RCS devices in profoundly hearing impaired children.

Common variance in amplitude envelope perception tasks and their impact on phoneme duration perception and reading and spelling in Finnish children with reading disabilities

ABSTRACTOur goal was to investigate auditory and speech perception abilities of children with and without reading disability (RD) and associations between auditory, speech perception, reading, and spelling skills. Participants were 9-year-old, Finnish-speaking children with RD (N = 30) and typically reading children (N = 30). Results showed significant group differences between the groups in phoneme duration discrimination but not in perception of amplitude modulation and rise time. Correlations among rise time discrimination, phoneme duration, and spelling accuracy were found for children with RD. Those children with poor rise time discrimination were also poor in phoneme duration discrimination and in spelling. Results suggest that auditory processing abilities could, at least in some children, affect speech perception skills, which in turn would lead to phonological processing deficits and dyslexia.

Bilinguals mind their language (mode): Vowel perception patterns of simultaneous bilingual and monolingual speakers.

It is well‐established that the speech perception abilities of monolingual speakers are highly tuned to the sounds of their native language, and that this language specificity affects how monolingual speakers distinguish the sounds of a non‐native language. The present study addressed how the speech perception skills of simultaneous bilingual speakers, who are native speakers of two languages, may be affected by control of active language mode. We tested monolingual (English and French) and simultaneous bilingual (English/French) adults in an identification and rating task with 42 vowels along a continuum from a high back rounded vowel (/u/) to a high front rounded vowel (/y/) that are both phonemic in French, with only the back vowel represented in English. Bilinguals completed the task in three language modes: English, French, and bilingual. As expected, monolingual speakers demonstrated a language‐specific perceptual pattern for the vowels. Bilingual participants displayed different perceptual patterns in each active language mode to accommodate the vowel categories relevant in the target language. These findings indicate that simultaneous bilinguals rely on a finely detailed perceptual space and are flexible as they adapt their perception to different language environments.

Brain, behavioral, and sociocultural factors in bilingual language learning.

Previous behavioral studies have shown improved sensitivity to native‐language contrasts and reduced sensitivity to non‐native phonetic contrasts when comparing 6–8‐ and 10–12‐month‐old monolingual infants. It has been argued that exposure to language dedicates neural networks to the acoustic properties of native‐language speech, and that, in adulthood, this commitment interferes with nonnative speech processing [native language neural commitment or (NLNC)]. There are very few studies on how early speech perception in bilinguals relates to future language advancement. Recently it has been shown that infants’ early native‐language speech perception skill predicts their later success at language acquisition. In the present investigation, we examined how brain measures of speech perception in bilingual infants and socio‐cultural factors of their environment predict later vocabulary growth. Our results showed excellent neural discrimination of both English and Spanish phonetic contrasts in 12‐month‐old infant...

Benefits of Short Interimplant Delays in Children Receiving Bilateral Cochlear Implants

To examine speech perception skills in quiet and noise in children using bilateral cochlear implants and to assess the influence of duration of bilateral deafness and interimplant delay. Prospective repeated measures. Tertiary academic referral center. Speech perception was assessed in 58 children with early-onset deafness; 51 received their first implant after less than 3 years of bilateral deafness and their second implant simultaneously or after a long (>2 yr) or short (6-12 mo) interimplant delay. Another seven children had longer periods of bilateral deafness (>3 yr) before the first implant and received their second after a long (>2 yr) interimplant delay. Mean (standard deviation) of bilateral implant use was 12.5 (7.9) months ranging from 6 to 36 months. Repeated measures in quiet were completed in three quiet and two noise (no spatial separation) conditions. In quiet, children listened with their right implant alone, left implant alone, and with both implants. In noise, children wore one implant in the experienced (or right for simultaneous group) ear and both implants. Speech perception scores were poorer in noise than in quiet, but significant improvements were found when bilateral rather than unilateral implants were worn. Improvements were greatest for children who were implanted with a short duration of bilateral deafness and a limited interimplant interval. Benefits of bilateral implantation in the short term are clearest in children with limited delays between implantation.

Performance of speech perception after cochlear implantation in DFNB1 patients

Conclusion: There were no apparent differences in speech performance after cochlear implantation between patients with biallelic GJB2 and/or GJB6 mutations and those with deafness of unknown aetiology. These data have important implications for the selection of prognostic indicators of the outcome of cochlear implantation. Objective: To compare performance after cochlear implantation in children with mutations in GJB2 (connexin 26) and/or GJB6 (connexin 30) and children with deafness of unknown aetiology. Subjects and methods: Genetic analysis and speech performance evaluation was determined in 24 patients with (n=11) and without (n=13) biallelic GJB2 and/or GJB6 mutations who underwent cochlear implantation. Speech perception skills were measured 12 and 24 months after surgery. Each patient was classified in accordance with the speech perception category (SPC). Results: Overall, the two groups showed similar significant improvement in speech perception after implantation.

Effects of classroom noise on the speech perception of bilingual children learning in their second language: Preliminary results

AbstractObjective: The objective was to determine the effects of noise on speech perception skills in immigrant children and to compare the results with those relative to monolingual matched peers. Study design: This was a case-control study, 11 immigrant children (aged 6–10 years) learning through their second language (L2) and 10 Italian-only-speaking matched peers. The speech-to-noise ratio (SNR) to obtain a 50% intelligibility (SRT) for Italian words had been measured by using an adaptive method. Results: For L2 learning children the SNR were +0.4dB (SD 2.1) with energetic ipsilateral masking (cocktail party) and -16.1dB (SD 2.5) with informational contralateral masking (continued discourse). For the control group the SNR were -0.5dB (SD 2.0) with energetic ipsilateral masking and -17.2dB (SD 3.2) with informational con-tralateral masking. With the energetical masking, SNR decreased as exposure to L2 increased; in contrast, the informational masking produced an opposing trend. Conclusion: Under advers...

Speech Development in Prelingually Deaf Children with Cochlear Implants

AbstractSince the early 1980s, cochlear implantation has been an approved method for treating profound bilateral sensorineural hearing loss in children. It is widely believed that the use of this device would significantly benefit young deaf children's development of speech and ability to participate in aural–oral communication. However, whereas significant improvement in speech reception and perception skills following implantation has been widely documented, cochlear prostheses as speech production aids have been studied less extensively. The main objective of this article is to review the work conducted on speech produced by prelingually deaf children following cochlear implantation. Cochlear implants and their functioning are described, as are the cognitive, social and clinical factors known to play a role in successful implantation of children. It is concluded that cochlear implantation may speed up speech production to near normal rates, but initial delays are not totally reversible. In addition, the variability in all performance measures is high, and the reasons for good and poor outcomes are only partly understood.

Assessing speech perception in young children and relationships with language skills

Few materials are available to assess speech perceptual skills in young children without hearing impairments. However, children with a range of developmental conditions are at risk of speech discrimination deficits. Tasks that reliably assess speech perception skills are thus necessary for research and clinical practice. The development and application of two speech perception tests are described. Data were collected from 105 children, aged 4–5 years, attending mainstream schools, on two tasks, mispronunciation detection and non-word XAB, in quiet and in a background of multi-talker babble. Children's receptive language skills were also measured. Performance on mispronunciation detection was significantly better than on the XAB non-word task, and significantly better in quiet than in babble. Performance significantly improved with age, and speech discrimination was significantly related to receptive language abilities. Scores obtained in quiet and in babble were highly correlated and findings suggest there may be no advantage to testing in noise, except to avoid ceiling effects on performance. These tasks prove useful in the assessment of young children who may have speech discrimination deficits.

Audiovisual asynchrony detection and speech perception in hearing-impaired listeners with cochlear implants: A preliminary analysis

This preliminary study examined the effects of hearing loss and aging on the detection of AV asynchrony in hearing-impaired listeners with cochlear implants. Additionally, the relationship between AV asynchrony detection skills and speech perception was assessed. Individuals with normal-hearing and cochlear implant recipients were asked to make judgments about the synchrony of AV speech. The cochlear implant recipients also completed three speech perception tests, the CUNY, HINT sentences, and the CNC test. No significant differences were observed in the detection of AV asynchronous speech between the normal-hearing listeners and the cochlear implant recipients. Older adults in both groups displayed wider timing windows, over which they identified AV asynchronous speech as being synchronous, than younger adults. For the cochlear implant recipients, no relationship between the size of the temporal asynchrony window and speech perception performance was observed. The findings from this preliminary experiment suggest that aging has a greater effect on the detection of AV asynchronous speech than the use of a cochlear implant. Additionally, the temporal width of the AV asynchrony function was not correlated with speech perception skills for hearing-impaired individuals who use cochlear implants.

Associations and Dissociations Between Psychoacoustic Abilities and Speech Perception in Adolescents With Severe-to-Profound Hearing Loss

To clarify the relationship between psychoacoustic capabilities and speech perception in adolescents with severe-to-profound hearing loss (SPHL). Twenty-four adolescents with SPHL and young adults with normal hearing were assessed with psychoacoustic and speech perception tests. The psychoacoustic tests included gap detection (GD), difference limen for frequency, and psychoacoustic-tuning curves. To assess the perception of words that differ in spectral and temporal cues, the speech tests included the Hebrew Early Speech Perception test and the Hebrew Speech Pattern Contrast test (L. Kishon-Rabin et al., 2002). All tests were conducted for the listeners with normal hearing at low and high presentation levels and for the participants with SPHL at 20 dB SL. Only GD thresholds were comparable across the 2 groups at similar presentation levels. Psychoacoustic performance was poorer in the group with SPHL, but only selected tests were correlated with speech perception. Poor GD was associated with pattern perception, 1-syllable word identification, and final voicing subtests. Speech perception performance in adolescents with SPHL could not be predicted solely on the basis of spectral and temporal capabilities of the auditory system. However, when the GD threshold was greater than 40 ms, speech perception skills were predictable by psychoacoustic abilities.