Figure 1 - uploaded by Mohd Normani Zakaria
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An example of typical acoustic reflex waveform and the onset acoustic reflex latency (ARL) calculation from a representative subject.
Source publication
In the field of auditory neuroscience, acoustic reflex is a useful clinical test for hearing diagnosis and site of lesion assessment. Nevertheless, the latency measurement of acoustic reflex has not been widely studied and more research efforts are warranted. The present study aimed to determine the influences age, gender and stimulus frequency
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Contexts in source publication
Context 1
... Upon the presentation of loud sounds, the stapedius muscles (in both ears) will contract causing the middle ear system to become stiff. Consequently, more sounds will be reflected rather than transmitted, to protect the vulnerable cochlea in the inner ear. By having a specialized device, this action can be conveniently recorded and documented. Fig. 1 shows an example of a typical acoustic reflex waveform recorded from a normal participant. This protective mechanism is typically absent in the conditions where the acoustic reflex pathway is affected such as conductive hearing loss, severe degree of sensorineural loss and impaired auditory brainstem (Katz et al., 2015;Margolis and ...
Context 2
... | January 2019| Volume 17 | Issue 01 | Page 145-150| doi: 10.14704/nq. 2019.17.01.1925 Zakaria MN., Acoustic Reflex Latency (ARL) Assessment in Malaysian Adults: The Effects of Age, Gender and Stimulus Frequency acoustic reflex testing was performed again but the pure tone stimuli were presented at 10 dB above ART. As illustrated in Fig. 1, the ARL was measured by calculating the latency difference between the onset of stimulus and the latency at 10% of maximum AR amplitude. For each trial, two recordings were made and averaged to produce reliable responses. All recordings were performed in a dedicated sound proof room within the Audiology Clinic, University ...
Citations
... Ethical approval for this study (registration number İ1- [14][15][16][17][18][19][20][21] was provided by the Ankara University Faculty of Medicine Clinical Research Ethics Committee, on 14 January 2021. ...
... The literature has shown that there is neither ear side effect nor gender difference in ARL. [1,18] Using the same impedance device and test measurement parameters as our study, Narayanan examined the latency parameters between the right and left ears of 30 female participants with normal hearing from 20 to 30 years. [6] No significant differences were observed at the frequencies 500, 1000, 2000, and 4000 Hz. ...
Objective
There are a limited number of studies on Acoustic reflex latency (ARL) test in the literature. In this study, we aimed to examine the ARL test results and parameters in young adults in Türkiye and evaluate the difference in interaural latency.
Materials and Methods
A total of 50 individuals with normal-hearing thresholds, 25 females and 25 males, between the ages of 18 and 35 years were included in the study. Parameters of ARL; 10% – on latency, 90% – on latency, 10% – off latency, and 90% – off latency were recorded and analyzed in 500, 1000, 2000, and 4000 Hz frequencies. Study results were compared between ears and genders.
Results
When comparing the right and left ears, ARL parameter values of men and women, 90% on and 10% off latency on the right and 90% on latency on the left ear, were found to be longer in women only at a frequency of 4000 Hz. At 500, 1000, and 2000 frequencies, no significant difference was observed between the genders. There was no interaural difference of ARL. As the frequency increased, it was observed that the ARL onset latencies were prolonged in both men and women.
Conclusion
Our study indicated that there was no interaural difference of ARL in normal-hearing subjects. İnteraural difference of ARL may provide diagnostic information clinically.
... Even though the acoustic reflex latency (ARL) has good potential in testing patients with peripheral and neural auditory disorders, it has not been extensively studied and its current literature is extremely limited (29,30). If compared to ART and ARD, measuring ARL is less straightforward and additional test parameters might be required (31). ...
Acoustic reflex test has been used routinely as a clinical tool for hearing diagnosis and site of lesion testing among children and adults. By measuring the presence and strength of stapedius muscle contraction upon loud sounds presentation, the status of acoustic reflex pathway (up to the brainstem region) can be conveniently documented. In clinical settings, acoustic reflex parameters including acoustic reflex threshold (ART) and acoustic reflex decay (ARD) are commonly used by clinicians for specific applications. Acoustic reflex latency (ARL), another acoustic reflex parameter, has received less attention and its literature is extremely limited. This paper provides a review of the literature on the essential aspects of acoustic reflex and its parameters. The diagnostic values and clinical applications of acoustic reflex are highlighted as intended. Special emphasis is given to ARL that has good potential for clinical applications. The possible reasons for the under-utilization of this acoustic reflex parameter are discussed accordingly. With the significant advancement of technology in this field, it seems essential to revisit and promote the use of ARL among clinicians and researchers. By using appropriate standards, techniques and measurements, the diagnostic values of ARL would be enhanced, which can be beneficial when testing patients with peripheral and central auditory disorders. Several research areas are proposed to further explore the essential features of ARL.
Background
The acoustic stapedius reflex is formed by the contraction of the stapedius muscle in the middle ear cavity when a loud sound is given to both ears. Changes in properties such as the intensity, frequency, duration, and speed of stimulus affect reflex responses.
Methods
As a result of the literature review conducted between 2005 and 2020, 2846 articles were reviewed and 30 articles evaluating the effects of stimulus changes on acoustic reflex responses were included in the study.
Main text
In the studies reviewed, it was observed that lower threshold values were obtained by using noise as a stimulus instead of pure sound. Different results were found regarding the duration and frequency of the stimulus. It has been reported that stimulus frequency does not have a significant effect on acoustic reflex delays and the acoustic stapedius reflex threshold increases in the presence of opposite side noise.
Conclusion
As a result of the studies reviewed, it was seen that the changes in many properties of the stimulus that activate the middle ear muscles affected the reflex response.
The concept of using DNA molecules for designing nano-scale electronic systems has attracted researcher’s attention due to the unique properties of DNA, such as self-assembly and self-recognition. Thus, increased number of studies, theoretically and experimentally, have been carried out to study the possibility of adopting DNA molecules in designing nanoscale thermoelectric devices. In this work, a general expression of the electron transmission probability that describes the electron transfer through one strand DNA chain has been derived using the steady-state-formalism by assuming one strand of DNA molecules as line model. The energy-dependent transmission was studied, then energy-and temperature-dependent Seebeck coefficient, and thermoelectric characteristics of four one strand DNA sequences: (A-A)10, (C-C)10, (G-G)10 and (T-T)10 are theoretically studied. According to the obtained results, it is found that the transmission behavior (magnitude and position) is varying with the type of DNA sequence. Also, the energy dependent Seebeck coefficient (S-E) curves clearly show a nonlinear energy-dependence, while the relationship between Seebeck coefficient and temperature (S-T) is linear. Thermoelectric power factor as a function of temperature was found to be enhanced with the temperature increment for the four types of DNA nucleobases. The highest values of thermoelectric power factor belong to thymine (120Wm-1K-2) and cytosine (60 Wm-1K-2), that nominate them as outstanding candidate thermoelectric materials to be adopted in the fabrication of one strand DNA-base nanoscale thermoelectric devices.
