Speech Pattern Contrast Research Articles

Speech perception in deaf and hard of hearing Arabic-speaking children

The rate of Deaf and Hard of Hearing (DHH) people is relatively large in native Arabic speakers in Israel. However, Arabic assessment tools are scarce. The present study reports the procedure of developing two speech perception assessment tools, which are used for hearing loss diagnosis, hearing aids fitting, cochlear implant mapping, and evaluation of progress following rehabilitation intervention. Our closed set test “Arabic Picture Speech Pattern Contrast” (ArPiSPAC), and word perception open-set test, “Arabic AB” (ArAB), were administered to 34 children with moderate to profound sensorineural hearing loss, hearing aids users, aged between 4;5—8;11. In addition, the ArPiSPaC was administered to 38 hearing children, aged between 2;6-5;5 in order to obtain a developmental hierarchy. For DHH participants, the findings showed that vowel contrasts were better perceived than consonants, and articulation manner was better perceived than articulation place. The hearing participants' phonological perception hierarchy differed in some interesting features from that of the DHH children. The mean percent of phoneme perception by DHH was M = 60.53%, (SD = 23.87), and the mean percent of word perception was M = 18.5%, (SD = 15.68). Voicing and pharyngealization contrasts revealed the largest Pearson correlation for phoneme and word perception.

Auditory Perception and Production of Speech Feature Contrasts by Pediatric Implant Users

The aim of the present research is to examine the relations between auditory perception and production of specific speech contrasts by children with cochlear implants (CIs) who received their implants before 3 years of age and to examine the hierarchy of abilities for perception and production for consonant and vowel features. The following features were examined: vowel height, vowel place, consonant place of articulation (front and back), continuance, and consonant voicing. Fifteen children (mean age = 4;0 and range 3;2 to 5;11) with a minimum of 18 months of experience with their implants and no additional known disabilities served as participants. Perception of feature contrasts was assessed using a modification of the Online Imitative Speech Pattern Contrast test, which uses imitation to assess speech feature perception. Production was examined by having the children name a series of pictures containing consonant and vowel segments that reflected contrasts of each feature. For five of the six feature contrasts, production accuracy was higher than perception accuracy. There was also a significant and positive correlation between accuracy of production and auditory perception for each consonant feature. This correlation was not found for vowels, owing largely to the overall high perception and production scores attained on the vowel features. The children perceived vowel feature contrasts more accurately than consonant feature contrasts. On average, the children had lower perception scores for Back Place and Continuance feature contrasts than for Anterior Place and Voicing contrasts. For all features, the median production scores were 100%; the majority of the children were able to accurately and consistently produce the feature contrasts. The mean production scores for features reflect greater score variability for consonant feature production than for vowel features. Back Place of articulation for back consonants and Continuance contrasts appeared to be the most difficult features to produce, as reflected in lower mean production scores for these features. The finding of greater production than auditory perception accuracy for five of the six features examined suggests that the children with CIs were able to produce articulatory contrasts that were not readily perceived through audition alone. Factors that are likely to play a role in the greater production accuracy in addition to audition include the lexical and phonetic properties of the words elicited, a child's phonological representation of the words and motor abilities, and learning through oro-tactile, visual, proprioceptive, and kinesthetic perception. The differences among the features examined, and between perception and production, point to the clinical importance of evaluating these abilities in children with CIs. The present findings further point to the utility of picture naming to establish a child's production accuracy, which in turn is necessary if using imitation as a measure of auditory capacity.

Auditory Development in Early Amplified Children: Factors Influencing Auditory-Based Communication Outcomes in Children with Hearing Loss

The purpose of this study was to determine the influence of selected predictive factors, primarily age at fitting of amplification and degree of hearing loss, on auditory-based outcomes in young children with bilateral sensorineural hearing loss. Forty-four infants and toddlers, first identified with mild to profound bilateral hearing loss, who were being fitted with amplification were enrolled in the study and followed longitudinally. Subjects were otherwise typically developing with no evidence of cognitive, motor, or visual impairment. A variety of subject factors were measured or documented and used as predictor variables, including age at fitting of amplification, degree of hearing loss in the better hearing ear, cochlear implant status, intensity of oral education, parent-child interaction, and the number of languages spoken in the home. These factors were used in a linear multiple regression analysis to assess their contribution to auditory-based communication outcomes. Five outcome measures, evaluated at regular intervals in children starting at age 3, included measures of speech perception (Pediatric Speech Intelligibility and Online Imitative Test of Speech Pattern Contrast Perception), speech production (Arizona-3), and spoken language (Reynell Expressive and Receptive Language). The age at fitting of amplification ranged from 1 to 72 mo, and the degree of hearing loss ranged from mild to profound. Age at fitting of amplification showed the largest influence and was a significant factor in all outcome models. The degree of hearing loss was an important factor in the modeling of speech production and spoken language outcomes. Cochlear implant use was the other factor that contributed significantly to speech perception, speech production, and language outcomes. Other factors contributed sparsely to the models. Prospective longitudinal studies of children are important to establish relationships between subject factors and outcomes. This study clearly demonstrated the importance of early amplification on communication outcomes. This demonstration required a participant pool that included children who have been fit at very early ages and who represent all degrees of hearing loss. Limitations of longitudinal studies include selection biases. Families who enroll tend to have high levels of education and rate highly on cooperation and compliance measures. Although valuable information can be extracted from prospective studies, not all factors can be evaluated because of enrollment constraints.

An On-Line Imitative Test of Speech-Pattern Contrast Perception (OlimSpac): Developmental Effects in Normally Hearing Children

The goal was to assess the effects of maturation and phonological development on performance, by normally hearing children, on an imitative test of auditory capacity (On-Line Imitative Test of Speech-Pattern Contrast Perception [OlimSpac]; Boothroyd, Eisenberg, & Martinez, 2006; Eisenberg, Martinez, & Boothroyd, 2003, 2007). Thirty-four hearing children (aged between 1;8 [years;months] and 6;7) were asked to imitate nonword utterances. Responses were evaluated by a blinded listener in an 8-alternative forced-choice task, giving information on the children's ability to convey, by imitation, information about 6 binary phonemic contrasts. Four children declined participation. Among 30 children aged 2;7 or older, performance improved significantly with age and varied with contrast. All children 3 years of age or older attained passing scores (7 or 8 correct responses in 8 binary trials) on at least 5 of the 6 contrasts. Post-alveolar consonant place was the contrast most often failed. When evaluated on a pass/fail basis, normally hearing children 3 years of age or older are likely to demonstrate auditory perception of most phonemic contrasts using this imitative test. Phonological development and other task-related factors have only a modest effect on performance by normally hearing children after 3 years of age. The effects of hearing loss, hearing age, sensory assistance, and listening experience in children with hearing loss remain to be determined.

Relationships between speech perception abilities and spoken language skills in young children with hearing loss

The goal of this study was to examine the relationships between scores obtained from measures of speech perception and language in a group of young children with hearing loss (HL). Eighteen children (mean age = 4.3 years) and their mothers participated in this study. Speech perception was measured using the online imitative test of speech pattern contrast perception (OLIMSPAC). Standardized language age equivalent scores were obtained using the Reynell developmental language scales-III. Number of word tokens, word types, and mean length of utterance (MLU) were extracted from the children's spontaneous language samples. Significant positive relationships were observed between children's OLIMSPAC scores and both standardized language scores (r ranging from 0.60 to 0.69; p <0.01) and all measures derived from children's spontaneous language samples (r ranging from 0.80 to 0.86; p<0.01). After controlling for child age, OLIMSPAC scores explained 34.1% of the variance in children's MLU. Using a new speech perception measure with reduced language demands, strong positive correlations were evident between speech perception and language skills for a young group of children with HL.

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.

Assessing Speech Pattern Contrast Perception in Infants

To assess perception of specific speech pattern contrasts in infants with normal hearing (NH) and infants with sensorineural hearing loss (HL). Prospective longitudinal and cross-sectional study. Tertiary referral center. Nine infants with NH and 11 infants with HL ranging from mild to profound. Speech pattern contrast perception was evaluated in infants with NH and HL using a new behavioral test called Visual Reinforcement Assessment of the Perception of Speech Pattern Contrasts (VRASPAC). VRASPAC assesses the infant's ability to distinguish the speech features of vowel height and place and consonant voicing, continuance, and place. Detection of a phonetic change is indicated by a conditioned head-turn response. Performance is reported as the percent confidence that responses are not random. The infants with NH attained high confidence scores for the vowel height and place contrasts used in this study. The infants with HL achieved high scores for the vowel height contrast regardless of degree of hearing loss. High scores were attained for the vowel place contrast by infants with losses less than 60 dB HL. Performance for the consonant contrasts was variable for all of the infants. Results from 1 infant assessed precochlear and postcochlear implantation indicated substantial improvement in speech pattern contrast perception with the implant. Perception of speech pattern contrasts in infants, particularly for the vowel contrasts, can be evaluated with a high level of confidence using VRASPAC. Consonant contrast perception is much more variable than vowel contrast perception and requires further investigation.

Perception of phonetic contrasts in infants: development of the VRASPAC

The VRASPAC (visual reinforcement assessment of the perception of speech pattern contrasts) is a test that assesses auditory perception of phonologically significant contrasts in infants by combining the visual reinforcement and change/no-change techniques with the speech pattern contrast concept. The contrasts convey vowel height, vowel place, and consonant voicing, manner and place. The infant habituates to a continuous repetition of a standard nonsense syllable and then is conditioned to respond, via head-turn response, to a contrasting syllable. Animated toys or cartoon images serve as the reinforcement. To date, 10 children have been tested on two early versions of the test; six children with normal hearing (9–34 months), two children with mild or moderate hearing loss using hearing aids (11–17 months), and two children with profound hearing loss using cochlear implants (36–38 months). The normal-hearing children responded consistently to the vowel and consonant contrasts. The hearing-impaired children responded consistently to vowel height only. Preliminary results suggest that the VRASPAC is a viable test for infants as young as 9 months and that performance is dependent on phonological development.

Validation of an on-line implementation of the Imitative test of Speech Pattern Contrast perception (IMSPAC).

The imitations of syllables by six children with sensorineural hearing loss were evaluated in a forced-choice procedure, providing information on the production and perception of ten phonetic contrasts. One listener responded on-line. Four listeners responded off-line, to recordings. When all listeners were unfamiliar with the talkers, on- and off-line scores were not significantly different. After a training study, in which the on-line listener was the teacher, on-line scores were 9%pts higher than off-line. There were also task-related improvements in the children's performance. The children's performance Increased considerably when text was presented with the auditory models. It is concluded that: children's imitations can provide a measure of auditory speech perception that is not necessarily limited by speech production; imitations can be evaluated on-line without affecting validity--provided that listener is not intimately familiar with the child's speech. Task-related learning on the part of the child should be taken into account when assessing changes over time.

Age-related changes in the visual perception of phonologically significant contrasts.

The purpose of the present study was to determine whether the ability to speechread phonological contrasts is influenced by age. Forty-eight subjects were equally represented in three age groups: 8-9 years, 11-12 years and adults (20-29 years). The Hebrew version of the Speech Pattern Contrast (HeSPAC) test was administered by speechreading alone. Results showed that: age influenced performance; performance was contrast-dependent (place contrasts highly visible, manner and vowel height partially visible and voicing contrast invisible); hierarchy of contrast performance was similar for all age groups; Hebrew and English differ in the visual accessibility to speech contrasts in final voicing only; and females were found to be poorer speechreaders than males for the partially visible contrasts. The results suggest that speechreading at the phonological level follows a developmental course. The implications of these findings extend to recommendations provided to children in noisy listening conditions, speechreading training in hearing-impaired children and those with central auditory processing disorders (CAPD), and to the design of sensory aids.

The perception of phonologically significant contrasts using speech envelope cues.

The observation that many cochlear implantees demonstrate high levels of speech recognition, despite limited or distorted spectral information, has motivated research on the importance of temporal information for the perception of speech. The purpose of this study was to measure the recognition of speech contrasts via only the speech envelope before and after training. Test stimuli consisted of eight segmental and two suprasegmental contrasts of the Hebrew Speech Pattern Contrast test using a binary forced-choice paradigm. Multiplying the speech waveform with white noise eliminated spectral information. Results show that stress, intonation and manner of articulation were very well perceived using only temporal information, whereas voicing and place of articulation were perceived above chance levels. Results also show that vowels were more susceptible to the removal of spectral information than consonants. These findings help to better understand speech perception performance of hearing-impaired individuals, including cochlear implant users. They may also have practical implications for aural rehabilitation and sensory aids design for the Hebrew speaking population.

Perception of Speech Pattern Contrasts Using a Multichannel Cochlear Implant

The ability to perceive for suprasegmental and eight segmental speech pattern contrasts was measured on 16 adult cochlear implantees using the Nucleus multichannel prosthesis with either F0-F2 (n = 9) or F0-F1-F2 (n = 7) coding. The results of this study indicated the following: (1) The Nucleus device provided significant access to the majority of suprasegmental and segmental speech contrasts. (2) Both one- and two-format coding strategies provided good access to speech pattern contrasts. (3) Considerable intersubject differences in performance were observed, but there was no evidence to suggest that these were related to either processing scheme. (4) Although the accessibility of speech contrasts varied, the pattern of perceptual performance was interpreted in terms of an acoustic/phonetic hierarchy. (5) The Speech Pattern Contrast (SPAC) test appears to be a practical procedure for analyzing the perception of phonologically salient information about the suprasegmental and segmental components of speech.

Amplitude compression and profound hearing loss.

Nine subjects with prelingually acquired, sensorineural, hearing loss were given a three-interval, forced-choice, test of speech pattern contrast perception under two amplification conditions. The first involved adjustment of the low and high frequency outputs of a two-channel Master Hearing Aid to each subject's highest comfortable level, but without compression of the short-term dynamic range of the signal. The second involved the additional compression of a 30 dB input range into the subject's dynamic range of hearing, as measured by the difference between speech awareness threshold and highest comfortable level, in each of the two channels. One of the subjects performed much better with compression than without. Among the other eight, however, there was a small but significant reduction of performance when compression was introduced. It is proposed that the one positive result is due to the increased audibility of speech cues made possible by amplitude compression. It is further proposed that the negative results are due mainly to the distortions of time-intensity cues introduced by amplitude compression. The results suggest that, in terms of potential access to meaningful speech cues, the addition of amplitude compression, to an otherwise optimized signal, is unnecessary, or even detrimental, for most profoundly deaf subjects, but could be beneficial for some.

Intelligibility of average talkers in typical listening environments.

Intelligibility of conversationally produced speech for normal hearing listeners was studied for three male and three female talkers. Four typical listening environments were used. These simulated a quiet living room, a classroom, and social events in two settings with different reverberation characteristics. For each talker, overall intelligibility and intelligibility for vowels, consonant voicing, consonant continuance, and consonant place were quantified using the speech pattern contrast (SPAC) test. Results indicated that significant intelligibility differences are observed among normal talkers even in listening environments that permit essentially full intelligibility for everyday conversations. On the whole, talkers maintained their relative intelligibility across the four environments, although there was one exception which suggested that some voices may be particularly susceptible to degradation due to reverberation. Consonant place was the most poorly perceived feature, followed by continuance, voicing, and vowel intelligibility. However, there were numerous significant interactions between talkers and speech features, indicating that a talker of average overall intelligibility may produce certain speech features with intelligibility that is considerably higher or lower than average. Neither long-term rms speech spectrum nor articulation rate was found to be an adequate single criterion for selecting a talker of average intelligibility. Ultimately, an average talker was chosen on the basis of four speech contrasts: initial consonant place, and final consonant place, voicing, and continuance.

Perception of Speech Pattern Contrasts via Cochlear Implants and Limited Hearing

The ability to perceive four suprasegmental and eight segmental speech pattern contrasts was measured in several subject groups. Mean performance of a group of House 3M cochlear implantees was similar to the mean performance of a group of Nucleus implantees with a trend toward better perception of suprasegmentals in the former and better perception of segmentals in the latter. Intersubject variability was higher in the Nucleus implantees, the best subject achieving an open set phoneme recognition score of 40%. Data from a single subject showed considerably superior performance in an aided ear with a 95-dB hearing loss than in an ear implanted with the House 3M device. Data from normal subjects listening to low pass filtered speech provide a basis for evaluating the results obtained by implantees. The results, though limited, illustrate the potential value of analytical tests such as the speech pattern contrast test used in these studies.

Measurement of speech feature perception in subjects with limited hearing

Many profoundly deaf subjects, aided by hearing aids or cochlear implants, are unable to recognize words or comprehend sentences by hearing alone but can perceive some phonologically significant contrasts, and thereby lipread more effectively. Measurement of this limited auditory ability typically requires the use of forced‐choice tests with their attendant problems of low efficiency, and the possibility of responses to cues that do not remain invariant across phonetic context. This paper describes a Speech Pattern Contrast (SPAC) test that measures the perception of four suprasegmental and eight segmental contrasts in a changing phonetic context. To improve efficiency, the binary contrasts are tested in pairs, and the test has been automated using a computer‐controlled, interactive system that also provides the option of feedback and replay. Evaluation of the SPAC test with hearing‐impaired subjects has shown only small, task‐dependent, learning effects. The interleaving of two‐binary choice tests does, ...