Development and Validation of a Virtual Moving Auditory Localization (vMAL) Test among Healthy Children

Introduction: The ability to localize sound sources is crucial for humans. Due to specific hearing disorders, the affected individuals may have problems to accurately locate the sound sources, leading to other unwanted consequences. Nevertheless, a simple auditory localization test (that employs moving auditory stimuli) is currently lacking in clinical settings. Essentially, the objectives of the present study were to develop a virtual moving auditory localization (vMAL) test that is suitable for assessing children and assess the validity and the reliability of this test. Materials and Methods: This study consisted of two consecutive phases. In phase 1, the required stimulus and the test set up for the vMAL test were established. Two loudspeakers were employed to produce five virtual positions, and eight different moving conditions were constructed. In phase 2, 24 normal-hearing Malaysian children (aged 7-12 years) underwent the vMAL test. The validity and the reliability of this test were then assessed using several validation measures. Fleiss Kappa and Spearman correlation analyses were used to analyse the obtained data. Results: The vMAL test was found to have good convergent validity (kappa = 0.64) and good divergent validity (kappa = -0.06). Based on the item-total correlation and Spearman coefficient rho results, this test was found to have good internal reliability (rho = 0.36-0.75) and excellent external (test-retest) reliability (rho = 0.99). Conclusions: in this study a new vMAL test was developed and proven to be valid and reliable accordingly for its intended applications. This test can be useful in clinical settings since it is simple to administer, cost-effective, does not take up much room, and can assess auditory localization performance in children. The outcomes of the present study may serve as preliminary normative data as well as guidelines for future auditory localization research

Earlier peak latencies may not fully reflect the robustness of cervical vestibular evoked myogenic potential to CE-Chirp stimulus

Dear Editor, We read with great interest the article by Ocal, et al. [1] that studied cervical vestibular evoked myogenic potential (cVEMP) results elicited by the conventional 500 Hz tone burst (TB) and narrow band Claus Elberling (CE)-chirp stimulus (360-720 Hz) among heathy adults. The chirp stimulus was found to produce significantly earlier P1 and N1 latencies, but P1N1 amplitudes were comparable between the two stimuli. The authors then concluded that “the chirp stimulus produces robust but earlier cVEMP than TB does” [1]. In this regard, we wish to highlight several issues worthy of consideration. The cVEMP latencies are influenced by the rise times of stimuli [2,3]. That is, stimuli with short rise times (such as clicks) would produce cVEMP with earlier latencies [2,3]. This is possibly because the otolith organs are sensitive to changes in acceleration over time [4]. The earlier cVEMP latencies for the chirp stimulus reported by Ocal, et al. [1] appear “insensible” and a further consideration is needed. The narrow band CE-chirp stimulus was designed with a specific envelope (and its onset is not steep) [5]. As such, it is expected that the chirp-evoked cVEMP would produce longer P1 and N1 latencies than the click-evoked cVEMP. This contemplation, in fact, has been demonstrated by Walther and Cebulla [6]. Since the commercially available CE-chirp stimuli were designed to optimally record auditory brainstem response (ABR), Walther and Cebulla [6] designed a band limited chirp stimulus (250-1,000 Hz) to record cVEMP and ocular vestibular evoked myogenic potential (oVEMP). As reported, cVEMP and oVEMP latencies were the longest for the chirp stimulus (relative to click and 500 Hz TB). Indeed, the earliest latencies were produced by the click stimulus [6]. In the study by Ocal, et al. [1], the earlier P1 and N1 latencies found with the narrow band CE-chirp stimulus (relative to the 500 Hz TB) were “unexpected” given the waveform and envelope of the two stimuli (i.e., the onset of both stimuli is not “equally” steep). Furthermore, the P1 latency was curiously early (around 10 ms), which is not consistent with studies utilizing clicks (stimuli with the steepest onset) [3,6]. Taken together, it appears that caution is advisable when using the CE-chirp stimulus in cVEMP recording. This stimulus was constructed to optimize ABR recording [5], and it may not “work” similarly in cVEMP recording. Moreover, the onset and offset times of CE-chirp stimulus were temporally “adjusted” during its construction so that it appears earlier than the conventional stimulus [7,8]. As such, the offset of chirp is the onset of click (0 ms) [7]. Therefore, it is not surprising to see earlier cVEMP latencies when tested with the CE-chirp stimulus. In contrast, using the custom-built chirp stimulus (without the temporal adjustment), cVEMP latencies were at least comparable to those of 500 Hz TB [6]. Collectively, the earlier cVEMP latencies elicited by the commercially available narrow band CE-chirp stimulus may not fully reflect the response robustness. When recording cVEMP with this stimulus, perhaps the amplitude is a better indicator for the robustness of cVEMP waveforms

The executive disruption model of tinnitus distress: Model validation in two independent datasets using factor score regression

This study presents the executive disruption model (EDM) of tinnitus distress and subsequently validates it statistically using two independent datasets (the Construction Dataset: n = 96 and the Validation Dataset: n = 200). The conceptual EDM was first operationalised as a structural causal model (construction phase). Then multiple regression was used to examine the effect of executive functioning on tinnitus-related distress (validation phase), adjusting for the additional contributions of hearing threshold and psychological distress. For both datasets, executive functioning negatively predicted tinnitus distress score by a similar amount (the Construction Dataset: β = −3.50, p = 0.13 and the Validation Dataset: β = −3.71, p = 0.02). Theoretical implications and applications of the EDM are subsequently discussed; these include the predictive nature of executive functioning in the development of distressing tinnitus, and the clinical utility of the EDM

The effect of masking on tinnitus: residual inhibition outcomes by different types of tinnitus maskers

The phantom auditory sensation or tinnitus can be supp-ressed by presenting external sounds. Residual inhibition (RI) method is typically used in clinical settings to determ-ine the suppressive ability of sounds towards tinnitus. The present study aimed to compare the RI outcomes produced by broadband noise (BBN). Amplitude modulated (AM) and ocean wave (OW) sounds in subjects with tinnitus. Employing a repeated measures design, fifteen eligible subjects with the main complaint of subjective and contin-uous tinnitus were enrolled in this study. The mean age of subjects was 47.0 years and 53.3% of them were males. Generally, most of the subjects showed the presence of RI (either full or partial RI) for all stimuli. The percentage of subjects who showed RI was the highest for the OW sound (86.7%). The percentage of subjects with RI effect was similar for BBN and AM tone (i.e., 73.3%). The non-parametric Friedman test found the duration of suppression to be not statistically different between the three stimuli (p = 0.162). To conclude, the occurrence of RI was the highest for the OW sound. On the other hand, the duration of RI was comparable between the three stimuli. The information gathered from this study might be useful for clinicians in choosing the optimum masker for sound therapy. Further studies with larger samples are encouraged to ascertain the present study findings

Preparation of Ion Exchange Membrane Chromatography by Modification of Polyethersulfone Membrane Through UV Grafting of [2-(Acryloyloxy) Ethyl] Trimethyl Ammonium Chloride and Acrylic Acid Monomer

Chromatographic separation of protein mixtures has become one of the most effective widely used means of techniques to purifying individual proteins. Packed bed chromatography is the common technique that is used configuration for the protein separation. However, packed bed chromatography has its some limitations during separation process such as high pressure drop and time consuming. Membrane chromatography then introduced to overcome the limitations of the packed bed chromatography. In the current research, polyethersulfone (PES) commercial membrane was converted into ion exchange (IEX) membrane chromatography by attaching [2-(acryloyloxy)ethyl] trimethyl ammonium chloride (AETMA) and acrylic acid (AA) monomer using UV light irradiation technique. The effect of AETMA and AA monomer concentration from 1.5 M to 2.0 M was studied. The IEX membrane was characterized in term of degree of grafting, changed of functional group as well as protein binding capacity using pure bovine serum albumin. For AETMA-grafted membrane, the binding capacity increase about the 65.32 % as the monomer concentration increase from 1.5 M to 2.0 M. While, for AA-grafted membrane, the binding capacity shows a huge increment when the monomer concentration was increase from 1.5 M to 2.0 M with amount 78.65 %

Adaptation of Teleaudiology Approach in Undergraduate Clinical Examinations: Lesson Learned

USM’s undergraduate audiology program began in 2005 and lasted eight semesters. Advances in information and communications technology (ICT) and the global COVID-19 epidemic are promoting telehealth in clinical teaching. This study used Krumm’s teleaudiology model for eight pediatric face-to-face clinical audiology examinations with final-year clinical students. Observation, Internet connectivity, and audiologist satisfaction confirmed the model’s feasibility. Lack of ICT resources and staff caused technical issues in most sessions. Internet speed was faster than early estimates. Live observation was more satisfying than recordings. We successfully implemented a trial version of an adapted teleaudiology approach that may be used to observe audiology clinical examinations. With minor changes, this approach can also be used for clinical observation in the future, particularly during the COVID-19 pandemic

Adaptation of Teleaudiology Approach in Undergraduate Clinical Examinations: Lesson Learned

USM’s undergraduate audiology program began in 2005 and lasted eight semesters. Advances in information and communications technology (ICT) and the global COVID-19 epidemic are promoting telehealth in clinical teaching. This study used Krumm’s teleaudiology model for eight pediatric face-to-face clinical audiology examinations with final-year clinical students. Observation, Internet connectivity, and audiologist satisfaction confirmed the model’s feasibility. Lack of ICT resources and staff caused technical issues in most sessions. Internet speed was faster than early estimates. Live observation was more satisfying than recordings. We successfully implemented a trial version of an adapted teleaudiology approach that may be used to observe audiology clinical examinations. With minor changes, this approach can also be used for clinical observation in the future, particularly during the COVID-19 pandemic

Cervical vestibular evoked myogenic potential (cVEMP) findings in adults with sensorineural hearing loss (SNHL): comparisons between 500 Hz tone burst and narrowband CE-Chirp stimuli

Abstract There has been a growing interest in studying the usefulness of chirp stimuli in recording cervical vestibular evoked myogenic potential (cVEMP) waveforms. Nevertheless, the study outcomes are debatable and require verification. In view of this, the aim of the present study was to compare cVEMP results when elicited by 500 Hz tone burst and narrowband (NB) CE-Chirp stimuli in adults with sensorineural hearing loss (SNHL). Fifty adults with bilateral SNHL (aged 20–65 years) underwent the cVEMP testing based on the established protocol. The 500 Hz tone burst and NB CE-Chirp (centred at 500 Hz) stimuli were presented to each ear at an intensity level of 120.5 dB peSPL. P1 latency, N1 latency, and P1–N1 amplitude values were analysed accordingly. The NB CE-Chirp stimulus produced significantly shorter P1 and N1 latencies (p  0.80). In contrast, both stimuli elicited cVEMP responses with P1–N1 amplitude values that were not statistically different from one another (p = 0.157, d = 0.15). Additionally, age and hearing level were found to be significantly correlated (r = 0.56, p < 0.001), as were age and cVEMP amplitude for each stimulus (p < 0.001). To conclude, since both stimuli were presented at an equivalent intensity level (in dB peSPL), the shorter P1 and N1 latencies of cVEMP produced by the NB CE-Chirp stimulus (centred at 500 Hz) were unlikely due to enhanced saccular stimulation. Another more sensible reason is the temporal adjustment of the chirp stimulus