Brainstem Representation of Auditory Overshoot in Guinea pigs, using Auditory Brainstem Responses

  Objective It is easier for a listener to detect a brief tonal signal presented in a longer masking noise by increasing the delay between the signal and the masker. This phenomenon (overshoot) is influenced by a reduction in cochlear amplification and to date, there is no objective tool to investigate it. Therefore, a different paradigm of the auditory brainstem response (ABR) was utilized to measure auditory overshoot. It was assumed that increasing the delay onset time (DOT) between a signal and a masker reduces the latencies of waves I and III. Materials & Methods Sixteen normal young male guinea pigs were tested. A tone burst stimulus (signal: 16 kHz, 5ms in duration) and wide-band noise (masker: 0.1-8.0 kHz, 100ms in duration) at three DOTs were used. To diminish the effect of the noise on waves, waveforms were subtracted from those derived from the noise burst alone. The absolute latency of the waves I and III, inter-peak latency of the waves I-III, and amplitude ratio of the waves III/I were compared for the 0, 30, and 100ms DOTs and five signal-to-noise ratios. Results The latencies of increased from the 0 to 30ms DOT and then decreased from the 30 to 100ms DOT (p < 0.001). No significant changes were observed in the latency waves at the 100ms DOT compared to the 0ms DOT (p > 0.005). Moreover, there were no significant differences between the three DOTs regarding the inter-peak latency and amplitude ratio of the waves (p <0.005). Conclusion The study results showed an overshoot-like electrophysiological effect using ABR. Therefore, an objective test was used to investigate auditory cochlear gain

Comparison of the Ling-6 Sound Test with Warble Tone Stimuli in Audiometry of Hearing-Impaired Children Using Hearing Aids Considering Different Prescriptions and Normal-Hearing Children

Background and Aim: Speech is a vital stimulus and the ultimate goal of hearing aid fitting to make the speech an audible signal. The purpose of this research was to investigate whether it is possible to track the threshold with speech phonemes and which of the two fitting methods of Desired Sensation Level version 5.0 (DSL v5.0) and National Acoustic Laboratories-Nonlinear 2 (NAL-NL2) provide better audibility for the phonemes. Methods: In this cross-sectional study, the unaided thresholds of 18 normal-hearing children and the aided thresholds of 15 hearing-impaired children aged 5-8 years were evaluated with two types of stimuli. DSL v5.0 and NAL-NL2 methods were used for hearing aid fitting in hearing-impaired children. Results: There was a significant relationship between the unaided and aided thresholds of each phoneme and the warble tone threshold at the corresponding frequency (p<0.01), except for the phoneme /s/. The results showed a significant difference between the aided thresholds of each phoneme and the upper limit of the speech banana in the corresponding frequency for each method (Z=–4.99, p≤0.001). Conclusion: The results showed that phonemes could be used to assess unaided and aided thresholds. In the first fit, both methods estimated the amount of amplification that caused the average aided thresholds for these six phonemes for moderate to severe hearing loss to be positioned within the speech banana range, except for the average aided thresholds for the /s/ phoneme in the NAL-NL2 method that was placed outside the range

Developing Persian Quick Speech in Noise With Words Containing High Frequency Phonemes: Determining its Validity and Equivalency

Background and Aims The quick speech in noise (Q-SIN) test shows how difficult it is to perceive speech in noise by determining signal-to-noise ratio (SNR) loss. The lists with high-frequency words have a better ability to identify SNR loss which have been created in Persian. Although a Persian version of Q-SIN with emphasis on high frequency is available، but there is no Q-SIN lists with high-frequency words; therefore,this study aims to develop new lists and the lists with high-frequency words for Q-SIN test and determine their equivalency in normal-hearing people which was condcuted in Tehran University of Medical Sciences.Methods The sentences were first developed. Then, their content validity and face validity were determined. In this regard، 36 sentences were used to make new Q-SIN lists and 36 sentences were used to make Q-SIN lists with high-frequency words. Based on the Q-SIN test development criteria، six regular lists (lists 1-6) and six lists with high-frequency words (lists 7-12) were tested on 46 people (23 males and 23 females) aged 18-35 with normal hearingResults The content validity index for new and high-frequency words lists were 0. 74 and 0. 736، respectively. The equivalency test results showed that among the first 6 lists، the lists no. 1, 2, 3, and 4 were equal. Among the six lists with high-frequency words, the lists no. 7, 8, 10, 11 were equal. There was no gender differences between six regular lists and high-frequency lists (P>0.05). Conclusion The Q-SIN word lists with equivalency can be used for normal-hearing people in clinical practice

Difference Limen for Intensity Following Monaural Use of Hearing Aid

Background and Aim: It is well established that adult sensory systems can reorganize following environmental changes; hearing aid stimulates a deprived auditory system resulting in changes in received stimuli and may be capable of inducing changes within the auditory system abilities such as difference limen for intensity. Hearing aid fitting induces perceptual and physiological modifications. The present study was conducted to evaluate the effects of hearing aid use on the intensity discrimination performance.Methods: The study group consisted of 30 monaural users of hearing aid with symmetrical moderate or moderately severe sensorineural hearing loss in both ears (15 males, 15 females), aged 45-65 years old with the mean of 57.73 and SD of 8.12 years. difference limen for intensity was measured at two frequencies, 500 Hz, 2000 Hz, and two intensity levels (10 dB SL, 40 dB SL). The results of fitted ears were compared with not-fitted ones.Results: The results of the study showed better difference limen for intensity scores at high frequency and high intensity levels. A significant lower difference limen for intensity in fitted ears was observed compared with not-fitted ears (p&lt;0.05), while there was no significant difference between the difference limen for intensity in the two groups at 500 Hz with 10 dB SL intensity (p=0.132).Conclusion: Hearing aid use affects intensity discrimination performance. Besides, perceptual modification following use of hearing aid is confirmed by our study which suggests a possible functional plasticity due to hearing aid use. However, further

The comparison of gains prescribed for digital behind-the-ear hearing aids using the manufacturer-specific and conventional prescriptive formulas

Background and Aim: There are several prescriptive formulas for covering a variety of hearing loss, each of which applies relatively different amplifications at different frequencies. This study aims to compare the gains prescribed for digital behind-the-ear (BTE) hearing aids by the Desired Sensation Level Multi-Stage [Input/Output] (DSLm[I/O]), National Acoustic Laboratories-non linear2 (NAL-NL2) and manufacturer-specific formulas at different levels of input intensity. Methods: The gain values in 12-channel BTE hearing aids prepared from four companies (Oticon, Phonak, ReSound and Siemens) were measured at three levels of input intensity (45, 65, and 85 dB SPL) and at a frequency range of 250−8000 Hz for two moderately severe flat and mild sloping to severe hearing losses by using the DSLm[I/O], NAL-NL2 and manufacturer-specific formulas in the Frye FP35 test box. Results: There was no significant difference between the four selected hearing aids in terms of prescribed gain values using the prescriptive formulas (p > 0.05). Conclusion: The DSLm[I/O] formula prescribes higher gain in the 12-channel BTE hearing aids from Oticon, Phonak and Siemens companies at all input intensities and frequencies for moderately severe flat and mild sloping to severe hearing losses compared to the NAL-NL2 formula and manufacturer-specific formulas (Voice Ali­gned Compression (VAC), Adaptive Phonak, Connexx Fit and audiogram+)

The Effect of the Nonlinear Frequency Compression Methods on the Recognition of Monosyllabic Words in Persian Language

Background and objective: The aim of all Frequency Lowering methods is access to high frequencies (HFs) for people with hearing loss. The advantage of these methods has been approved for improving speech perception and limitations reduction of affected people. One of these method is Nonlinear Frequency Compression that reduces the bandwidth of frequency band. This study was carried out to compare the Adaptive Nonlinear Frequency Compression (ANFC) with original algorithm of Nonlinear Frequency Compression (NFC) and Conventional Processing (CP). Material and Methods: Thirty people in the range of 18-40 years old with ski-sloping hearing loss were evaluated. The presence of cochlear dead region at least in one of the frequencies of 1500, 2000, 3000 and 4000 Hz was proved in all cases by performing the Threshold Equalizing Noise test (TEN (HL)). The evaluation was carried out using monosyllabic balanced-word lists in Persian language. Each of Lists used for recognition in one of the three processing modes such as ANFC, NFC and CP which it has been performed in the free field at 90 centimeters distance of the speaker and 0° azimuth.  Results: The scores of frequency compression algorithms are better than CP and it leads to improve recognition whereas the scores of NFC and ANFC were similar. In addition, it is not dependent to gender, the obtained scores in three processing modes.  Conclusion: It is more useful for a person with ski-sloping hearing loss to use hearing aids with frequency compression technology rather than CP. In fact, frequency compression gives them a better speech perception, but the effect of the two different algorithms is similar

Gap Pre-pulse Inhibition of the Cortical Auditory Evoked Potentials as a Possible Objective Pinnitus Assessment Tool

ObjectivesThe objective assessment tests overcome the variability of subjective methods. Cortical recordings with gap pre-pulse inhibition of the acoustic startle reflex stimulus have been used as objective tinnitus assessments in humans. This study aims to investigate this possible objective tinnitus test and compare gap-induced inhibition in different stimulus parameters and brain regions.Materials &amp; MethodsTwenty People (18-50 years old) without hearing loss and tinnitus were included. The sound stimuli consisted of continuous background noise with a loud startle tone preceded by a silent gap (20 and 40 ms duration, 120 and 150 ms distance from the startle). The N1-P2 complex amplitude and topoplot maps were extracted in 27-channel cortical response recording after signal processing. Four brain regions of interest (ROI) of anterio-frontal, centro-frontal, right, and left temporal were investigated. ResultsThe results showed that the maximum inhibition occurred in a 40 ms gap duration and 150 ms distance in all 4 ROIs. In comparing ROIs, the centro-frontal and left temporal regions revealed the most inhibition (p&lt;0.05). The decrease in the amplitude of the N1 and P2 in that region could also be traced in the 100 and 200 ms topoplots.ConclusionGap-induced inhibition was observed in all gap-embedded stimuli and all ROIs. However, the 40-150 mode and centro-frontal and left temporal regions had maximum inhibition in normal subjects. It provides a promising tool for objectively assessing tinnitus in humans with particular implications in children

The Effects of a Home Personal Computer-based Auditory Training Program on the Binaural Listening Skills of Children With Specific Learning Disability: A Protocol for a Randomized Clinical Trial

Background and Objectives: A high prevalence of central auditory processing disorders has been reported in children with learning disabilities. One of the crucial auditory processing disorders in these children is a binaural processing problem. Binaural hearing leads to improved auditory performance in noisy situations. This research aims to develop an auditory training program based on binaural interaction at the brainstem level and to investigate its effect on the binaural listening skills of children with a specific learning disability. Methods: After developing the rehabilitation program and determining its validity, this intervention study is conducted in three stages. The first stage includes baseline assessments, the second stage includes the implementation of rehabilitation intervention and the third stage consists of the re-implementation of the tests of the first stage once immediately after intervention and then once after 45 days of training. Masking level differences (MLD), Persian auditory recognition of words in noise (PARWIN), and binaural speech-auditory brainstem response (Speech-ABR) tests are the primary outcome measures. Persian randomized dichotic digits test (PRDDT), Persian pediatric competing word test (PPCWT), Persian pediatric competing sentences test (PPCST), and Persian version of the auditory processing disorder questionnaire (APDQ-P) were included as secondary outcome measures. The sample size in each intervention and control group was 15 people and the duration of training was 3 months. Conclusion: Considering the importance of brainstem function in binaural hearing, it is recommended to investigate the effectiveness of the developed binaural interaction training program in improving hearing in background noise in children with specific learning disabilities

A Study of the Central Auditory Function in Stutters by Masking Level Difference and Synthetic Sentence Identification Tests

Background and Aim: There are evidences that indicate a relationship between auditory processing disor¬ders and stuttering,¬ and any disorder in the central auditory function can be at least one of the underly¬ing causes of stuttering. Even though, using the most state of the art radiographic technologies, i.e. MRI, no definitive answer has been given in relative to this question. In this research, using Mask-ing Level Difference (MLD) and Synthetic Sentence Identification (SSI) tests, the central auditory func¬tion of stutters and normal group was evaluated.Materials and Methods: In this study was analytic cross-sectional, fifteen male patients with stutter-ing and 15 male normal cases with the age range from 16 to 40 years (average age 26.78 year) were evalu¬ated. SSI-ICM, SSI-CCM and MLD tests were performed. The results were compared in both groups.Results: Although stutterers mean MLD was less than that of normal group, the different was not signifi¬cant between stutters and normal group in SSI test in right ear at negative MCRs. There was a signifi¬cant difference in ICM state, but in CCM state, there was no significant difference between the aver¬age score of two groups in various MCRs.Conclusion: The findings of this research is compatible with those of similar researches about the SSI test and the pattern of results, probably indicates a partial dysfunction of brainstem in some of the stutters

Investigating the technology-based

No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means without the prior permission in writing of the publisher, nor be otherwise circulated in any form of binding or cover other than that in which it is published and without a similar condition including this condition being imposed on the subsequent purchaser. 1 Investigating the technology-based innovation gap for the United Kingdom Executive summary This report investigates the gap in technology-based innovation performance and policy between the UK and other leading nations. Assuming the importance of innovation for improvements in productivity and hence economic growth, the report gathers the available evidence on innovation performance in the UK and asks where improvements could be made in the UK’s policy framework to improve innovation outcomes. Increasing challenges from developed and emerging economies The UK’s position as a leading nation, in terms of innovation and overall economic performance, is under threat. The United States is taking a strongly pro-active approach to renewing their policy framework to support innovation, with numerous bills recently introduced in the US Congress. At the same time, China has doubled its national investment in R&amp;D between 199