The study aimed to develop Mandarin speech perception tests for Malaysian Chinese children. Two tests were developed which were the Syllabic Pattern Perception Test (SPPT) and the Tone Perception Test (TPT). Both tests were designed for children aged between three to six years-old. A total of 80 normal hearing children aged 3 years to 6 years and 11 months from several kindergartens around Kuala Lumpur and Ipoh participated in this study. Results showed that the mean scores for the SPPT did not differ significantly across age (p > 0.05), possibly due to a ceiling effect. Although the SPPT showed relatively low test-retest and inter-rater Spearman correlation coefficients (r = 0.68 for correct syllable pattern response and r = 0.38 for correct item response), the scores were highly repeatable in both test-retest and interrater conditions. For the TPT, the mean scores of five and six year old children were significantly higher than three year old subjects while the mean score of four year old subjects was significantly poorer than the six years old. The test-retest and inter-rater reliability were high and the coefficients approximated 0.80 (p < 0.05). For both tests, gender and dialects or languages used as the second language did not have significant effect on the test scores. Content validity evidence was also collected from a group of panelists. In conclusion, SPPT and TPT are reliable and valid Mandarin speech tests to be used on Malaysian Chinese children who speak Mandarin.
The Ministry of Health (MoH) commenced the National Cochlear Implant (CI) Program in 2008. As of November 2014,
the program has implanted 205 individuals with hearing losses, many of whom are pediatric recipients (71%) with
prelingual deafness. This study aimed to profile the prelingually deafened pediatric cochlear implant recipients under the
MoH CI program. The data reported here were from a total of 121 recipients (82.8%) from all the nine satellite hospitals
in the program. There were 58 males and the majority of the cases were Malay (66.9%). From the cases reviewed 39
(32.2%) were high risk for permanent hearing loss and the majority (46%) had multiple risk factors. In this cohort,
only 12 children (9.9%) were identified through the newborn hearing screening (NHS) program. The age of diagnosis of
hearing loss ranged from 1 to 46 months with a mean age of 24.3 ± 10.2 months. Hearing aids were fitted at the age of
4 to 46 months with a mean of 27.5 ± 9.9 months. The average age of implantation was 41.5 ± 10.3 months. The mean
overall waiting period from the first visit to the audiologist to the time when the cochlear implant was activated was 18.5
± 9.1 months. Descriptive findings indicate that the children received their implants at a relatively late age for speech
and language development. The existing national NHS program needs to be tighten and strengthen so that it can be the
main feeder for the pediatric CI program under the MoH. Subsequently, it is hoped that early identification of hearing
loss will lead to earlier age of implantation among the pediatric patients in the future.
Difficulty of understanding speech in noise among the elderly necessitates the need for Auditory Training which has made a renewal of interest in the last decade with the auditory training applications. This interest is perhaps spurred by advances in computer-based technology. In computer-based auditory training, speech signals are considered as auditory training stimuli where input speech signals need to be verified prior to training as the speech signals are mixed with noise signals. Computer-based Auditory Training System can be embedded with input speech verifying module. Input speech verifying module is employed with speech and noise separator simulator. This simulator needs to guarantee accurate separation of speech from noise signals. Therefore, in this research, Exploratory Projection Pursuit (EPP) technique under semi-Blind Source Separation (BSS) method is intended to separate the speech source signals which are mixed with competing speech (multitalker speech babble). This training uses Malay language based sentences which differ in word length and hence number of sample values. The experimental simulation considers two-channel random, linear mixing of speech sources and competing speech. The aim of this study is to evaluate the performance of source separation using the anticipated EPP technique for various sample values of speech signals which varies in time duration due to word length dissimilarity. Simulation results show that EPP technique is feasible for source separation. As a consequence, high correlation value of r ≥ 0.99 is obtained between extracted speech signal and original speech signal for all categories of speech signals. It is further verified by the maximum nongaussianity of extracted speech signal which has high kurtosis value of 32 approximately.
There is a lack of population-based data on prevalence of hearing loss in Malaysia. The purpose of this population-based study was to determine the prevalence of hearing loss and its risk factors among 382 older adults aged 60 years and above, recruited through multistage random sampling in Selangor. Hearing level was measured using pure tone audiometry. Hearing loss was classified into at least mild hearing loss and significant hearing loss based on the pure tone average (PTA) of 0.5, 1, 2 and 4 kHz. The examination also included face-to-face interview on hearing related medical history, noise exposure and hearing aid use. Overall, the prevalence of at least mild hearing loss and significant hearing loss were 73.6% (95% CI: 69.4 - 77.4) and 24.6% (95% CI: 20.8 - 28.7), respectively. The odds for at least ‘mild hearing loss’ were male gender, Chinese ethnicity, residing in urban areas, had no formal education or primary school education and history of hypertension. The risk for ‘significant hearing loss’ was significantly higher in males, those who lived in urban areas and elderly with cognitive impairment. Chinese and Indian ethnicities had significantly lower risks than Malay ethnic to have significant hearing loss. Despite the high prevalence of hearing loss, only 4.4% who might benefit from hearing aids wore them. In conclusion, findings from this study show high prevalence of hearing loss among the elderly population. Given the significant association between hearing loss and cognitive impairment, future studies should explore the role of hearing amplification in alleviating or slowing the progress of cognitive decline.
Cochlear implant (CI) is the main intervention option for people with severe and profound sensorineural hearing loss.
The purpose of this study was to investigate the auditory performance of a group of prelingually deafened paediatric
cochlear implant users using direct speech perception measures (objective) and a parental questionnaire (subjective)
and to identify significant demographic factors that might contribute to their performance. A total of 48 children from the
Cochlear Implant Program under the Malaysian Ministry of Health with hearing age of 12 to 89 months (mean = 42.60
± 19.46 months) participated in this study. The speech perception test was conducted using selected tests from the Malay
version of the Evaluation of Auditory Response to Speech (EARS) while parental views of the children’s performance were
collected using the Malay version of the Parents’ Evaluation of Aural/Oral Performance of Children (PEACH) questionnaire.
The recorded speech stimuli were presented to the children in a free field at approximately 65 dB SPL in a sound treated
room. The speech perception test results were then categorized using the Malay version of the Categories of Auditory
Performance Index (My-CAPI) with 10 categories ranging from ‘0’ to ‘9’. Results showed that most of the children (N = 20,
41.7%) were performing at category 2 of My-CAPI (limited closed set speech perception) with three children achieved the
maximum category 9 (advanced open-set sentences in noise). Communication mode was the only demographic factor that
significantly correlated with the My-CAPI and PEACH scores (p < 0.01). Pearson correlation coefficient showed a strong
relationship between the PEACH scores and My-CAPI levels (p < 0.01; r = 0.71) suggesting that the PEACH questionnaire
can be used as an indicator of the auditory performance if the speech perception tests cannot be performed. The findings
suggest that the majority of the CI children tested in this study had not achieved satisfactory auditory performance and that the use of oral communication mode was the main
factor associated with better auditory outcomes.
Despite a vast number of studies that were focused on the roles of superior temporal gyrus (STG) and cerebellum as sensory
area, little is known about their involvement in cognitive function such as attention and perception. The present fMRI
study aimed to identify this cognitive role from brain activation profile of STG and cerebellum obtained from an arithmetic
addition task. Eighteen healthy right hand dominance male adults participated in this study. They were instructed to solve
single-digit addition tasks in quiet and noisy background during the fMRI scan. Both the in-quiet and in-noise addition
tasks activated the bilateral STG and cerebellum (lobule VI and lobule VII) significantly but differentially. In both quiet
and noisy conditions, STG activation is dominant in the left hemisphere while cerebellum showed a right hemisphere
dominance. Bilateral STG and cerebellum (lobule VI) activation decreasedin noise, conversely cerebellum (lobule VII)
activation increased in noise. These asymmetrical activation indicated hemispheric lateralization and differential behaviors
of both brain areas in different environment while performing simple arithmetic addition task.
Proses penuaan seringkali dikaitkan dengan kemerosotan sistem kognitif. Kemerosotan tersebut bermula seawal usia dua puluhan dan berterusan secara linear. Walau bagaimanapun, kesan penuaan ke atas ciri kehubungan antara kawasan otak masih belum difahami. Dalam kajian ini, pengimejan resonans magnet kefungsian (fMRI) digunakan untuk mengkaji kesan penuaan ke atas kehubungan otak yang terhasil daripada tugasan mengulang secara terbalik (BRT). Subjek normal dalam empat kumpulan umur iaitu 20-29 tahun (n=14), 30-39 tahun (n=14), 40-49 tahun (n=10) dan 50-65 tahun (n=14) mengambil bahagian dalam kajian ini. Stimulus BRT terdiri daripada satu siri lima perkataan yang diberi secara auditori. Pemetaan statistik berparameter (SPM) dan pemodelan sebab dan akibat dinamik (DCM) digunakan untuk menentukan pengaktifan dan kehubungan otak. Sebanyak 200 model kehubungan intrahemisfera dan 150 interhemisfera dibina bagi menguji kewujudan gandingan antara girus temporal superior (STG), girus Heschl (HG), talamus (TH) dan girus presentral (PCG) kesemua subjek. Keputusan DCM menunjukkan subjek keempat-empat kumpulan umur menggunakan kehubungan intrahemisfera yang sama semasa tugasan BRT. Kehubungan interhemisfera pula didapati berubah menjadi semakin kompleks apabila usia meningkat. Perubahan tersebut didapati bermula pada usia 40 tahun. Keputusan ini menyokong penemuan terdahulu bahawa penuaan menyebabkan perubahan pada sistem neuron otak seterusnya mempengaruhi pemprosesan kognitif.
This paper describes the systematic process followed in the development of culturally appropriate equalized speech-in-noise sentences suitable for use in an adaptive Speech-In-Noise training protocol for adults in Malaysia. The process involved three iterative phases of development. They were (1) analysis, (2) design and (3) development phases. In the analysis phase, important variables that needed to be considered for speech-in-noise materials were identified through literature review and discussion with the experts in the field. Next, in the design phase, the compilation and formation of sentences, evaluation of naturalness and recording of the speech materials were done. The last phase was the development phase which involved the evaluation of performance intensity function and equalization of intelligibility. The final outcome of these phases were 171 sentences with equal intelligibility that can be used interchangeably in a speech-in-noise training protocol for adults in Malaysia.
Proses penuaan seringkali dikaitkan dengan kemerosotan pada sistem kognitif. Kemerosotan kognitif bermula seawal
usia dua puluhan dan berterusan secara linear. Selain itu, kemerosotan kognitif juga menjadi lebih nyata dengan
kehadiran hingar latar. Walau bagaimanapun, kesan penuaan ke atas mekanisme pemprosesan persepsi pertuturan
menggunakan tugasan mengulang secara terus (FRT) dalam senyap dan hingar belum difahami dengan jelas. Dalam
kajian ini, pengimejan resonans magnet kefungsian (fMRI) digunakan untuk membandingkan kesan penuaan ke atas
kehubungan efektif otak yang terhasil daripada tugasan FRT ke atas subjek normal dengan empat kumpulan umur yang
berlainan iaitu 20 - 29 tahun (n = 15), 30 - 39 tahun (n = 15), 40 - 49 tahun (n = 10) dan 50 - 65 tahun (n = 14). Satu siri
lima perkataan yang diselang-seli dalam keadaan hingar dengan senyap diberikan secara auditori. Pemetaan statistik
berparameter (SPM8) dan pemodelan dinamik penyebab (DCM10) digunakan untuk menentukan kehubungan efektif otak.
Kawasan yang terlibat dalam pembinaan model kehubungan efektif otak adalah STG, HG dan PCG. Model optimum yang
dipilih dalam kajian ini adalah model yang menunjukkan keseimbangan antara ketepatan dan kesukaran. Keputusan
fMRI kehubungan efektif menunjukkan bahawa komunikasi antara intrahemisfera tidak berubah dengan menggunakan
tugasan FRT ini apabila seseorang semakin berusia, tetapi komunikasi antara interhemisfera menjadi semakin kompleks.
Kajian ke atas sifat kehubungan efektif dalam korteks auditori dilakukan ke atas lima orang subjek Melayu lelaki sihat berumur antara 20 hingga 40 tahun menggunakan pengimejan resonans magnet kefungsian (fMRI), pemetaan statistik berparameter (SPM5) dan pemodelan dinamik penyebab (DCM). Paradigma pengimejan senyap digunakan untuk mengurangkan artifak bunyi pengimbas di atas imej kefungsian. Subjek dikehendaki menumpukan perhatian kepada stimulus hingar putih yang diperdengarkan secara binaural pada keamatan 70 dB lebih tinggi daripada aras pendengaran manusia normal. Pengkhususan kefungsian dikaji menggunakan perisian SPM5 yang berasaskan Matlab melalui analisis kesan malar (FFX), kesan rawak (RFX) dan konjunksi. Analisis individu ke atas semua subjek menunjukkan pengaktifan bilateral yang tidak simetri di antara korteks auditori kanan dan kiri pada kawasan Brodmann (BA)22, 41 dan 42 melibatkan korteks auditori primer dan sekunder. Tiga kawasan auditori di korteks auditori kanan dan kiri tersebut dipilih untuk penentuan kehubungan efektif melalui pembentukan sembilan model rangkaian. Kehubungan efektif ditentukan ke atas empat daripada lima subjek dengan mengecualikan seorang subjek yang mempunyai koordinat BA22 yang terletak terlalu jauh daripada koordinat BA22 yang diperoleh daripada analisis kumpulan. Keputusan DCM menunjukkan kewujudan kehubungan efektif di antara ketiga-tiga kawasan auditori yang dipilih di kedua-dua korteks auditori. Pada korteks auditori kanan, BA42 dikenalpasti sebagai pusat masukan dengan kehubungan efektif satu arah selari BA42 → BA41 dan BA42 → BA22. Walau bagaimanapun, untuk korteks auditori kiri, pusat masukan adalah BA41 dengan kehubungan efektif satu arah selari BA41→BA42 dan BA41→BA22. Kehubungan di antara kawasan auditori yang mengalami pengaktifan mencadangkan kewujudan lintasan isyarat dalam korteks auditori walaupun semasa subjek mendengar bunyi hingar.
In this study, the asymmetry of the main effects of action, background and tonal frequency during a pitch memory processing
were investigated by means of brain activation. Eighteen participants (mean age 27.6 years) were presented with low and
high frequency tones in quiet and in noise. They listen, discriminate and recognize the target tone against the final tone
in a series of four distracting tones. The main effects were studied using the analysis of variance (ANOVA) with action (to
wring (rubber bulb) vs. not to wring), background (in quiet vs. in noise) and frequency (low vs. high) as the factors (and
levels respectively). The main effect of action is in the right pre-central gyrus (PCG), in conformation with its contralateral
behavior. The main effect of background indicated the bilateral primary auditory cortices (PAC) and is right lateralized,
attributable to white noise. The main effect of frequency is also observed in PAC but bilaterally equal and attributable to
low frequency tones. Despite the argument that the temporo-spectral lateralization dichotomy is not especially rigid as
revealed by the main effect of frequency, right lateralization of PAC for the respective main effect of background clearly
demonstrates its functional asymmetry suggesting different perceptual functionality of the right and left PAC.
High sensitivity signal detection for a sparse temporal sampling (STS) functional magnetic resonance imaging (fMRI) is compensated by the increase in the number of scans (Ns) and consequently the scan time. A long scan time would result in fatigue and restlessness in participants, while a short scan time is undesirable for an STS-fMRI due to insufficient Ns for averaging. The purpose of this study was to determine the Ns practically sufficient for a sparse fMRI study. Eighteen participants were presented with white noise during a sparse fMRI scan. The height extent of activation was determined via t statistics and region of interest (ROI) based percentage of signal change (PSC). The t statistics and PSC for Heschl’s gyrus (HG) and superior temporal gyrus (STG) during which the participants listened to the white noise were calculated for different number of scans which were 6, 12, 18, 24, 30 and 36. The t statistics and PSC values calculated for the bilateral HG and STG qualitatively indicated a minimal change over Ns = 12 to 36. Both ROIs showed a consistent common right lateralization of activation for all Ns, indicating the right-hemispheric dominance of auditory cortex in processing white noise stimulus. It was proposed that for a sparse fMRI study, Ns may practically fall between 12 and 36