Auditory Recognition of Digit-in-Noise under Unaided and Aided Conditions in Moderate and Severe Sensorineural Hearing Loss

Background and Objectives@#The speech-in-noise test is typically performed using an audiometer. The results of the digit-in-noise recognition (DIN) test may be influenced by the flat frequency response of free-field audiometry and frequency of the hearing aid fit based on fitting rationale. This study aims to investigate the DIN test in unaided and aided conditions. Subjects and @*Methods@#Thirty four adults with moderate and severe sensorineural hearing loss (SNHL) participated in the study. The signal-to-noise ratio (SNR) for 50% of the DIN test was obtained in the following two conditions: 1) the unaided condition, performed using an audiometer in a free field; and 2) aided condition, performed using a hearing aid with an unvented individual earmold that was fitted based on NAL-NL2. @*Results@#There was a statistically significant elevation in the mean SNR for the severe SNHL group in both test conditions when compared with that of the moderate SNHL group. In both groups, the SNR for the aided condition was significantly lower than that of the unaided condition. @*Conclusions@#Speech recognition in hearing-impaired patients can be realized by fitting hearing aids based on evidence-based fitting rationale rather than by measuring it using free-field audiometry measurement that is utilized in a routine clinic setup.

The Effects of Hearing Aid Digital Noise Reduction and Directionality on Acceptable Noise Level

OBJECTIVES: Two main digital signal processing technologies inside the modern hearing aid to provide the best conditions for hearing aid users are directionality (DIR) and digital noise reduction (DNR) algorithms. There are various possible settings for these algorithms. The present study evaluates the effects of various DIR and DNR conditions (both separately and in combination) on listening comfort among hearing aid users. METHODS: In 18 participants who received hearing aid fitting services from the Rehabilitation School of Shahid Beheshti University of Medical Sciences regularly, we applied acceptable noise level (ANL) as our subjective measure of listening comfort. We evaluated both of these under six different hearing aid conditions: omnidirectional-baseline, omnidirectional-broadband DNR, omnidirectional-multichannel DNR, directional, directional-broadband DNR, and directional-multichannel DNR. RESULTS: The ANL results ranged from −3 dB to 14 dB in all conditions. The results show, among all conditions, both the omnidirectional-baseline condition and the omnidirectional-broadband DNR condition are the worst conditions for listening in noise. The DIR always reduces the amount of noise that patients received during testing. The DNR algorithm does not improve listening in noise significantly when compared with the DIR algorithms. Although both DNR and DIR algorithms yielded a lower ANL, the DIR algorithm was more effective than the DNR. CONCLUSION: The DIR and DNR technologies provide listening comfort in the presence of noise. Thus, user benefit depends on how the digital signal processing settings inside the hearing aid are adjusted.

The Acceptable Noise Level Benefit From Directionality for Listeners With Severe Hearing Loss

OBJECTIVES: Directional microphone technology can enhance the speech intelligibility and listening comfort of listeners with hearing impairment. The main aim of this study is to investigate and compare the benefit derived by listeners with severe hearing loss from directional microphone technology with that derived by listeners with moderate hearing loss. METHODS: The acceptable noise levels (ANLs) of two groups of listeners with moderate or severe hearing impairment (17 subjects in each group) were measured under unaided, omnidirectional-baseline-aided, and directional-aided conditions. RESULTS: Although the absolute ANL of the listeners in the severe hearing loss group was significantly higher than that of the listeners in the moderate hearing loss group, their derived benefit was equivalent to that derived by the listeners in the moderate hearing loss group. ANL and hearing loss degree were significantly related. Specifically, the ANL increased with the severity of hearing loss. CONCLUSION: Directional microphone technology can provide the benefits of listening comfort to listeners with severe hearing loss.

Educational level and pseudohypacusis in medico- legal compensation claims: a retrospective study

Pseudohypacusis or the intentional feigning of hearing loss is a challenging situation in the medicolegal evaluation of hearing levels. Few studies have been performed on predisposing factors that make compensation claims susceptible to malingering. The goal of this study was to investigate the relationship between educational level and frequency of pseudohypacusis in a group of medico-legal clients

Retrospectively, we studied the files of subjects [n=421] referred to the audiology clinic of a government hospital during a 12 month period. Educational levels of the individuals with and without pseudohypacusis were compared by the Chi-square test. The results show that individuals with pseudohypacusis have lower educational levels than cooperative clients. The relative frequency of individuals with pseudohypacusis among illiterates [43.5%] was clearly higher than individuals with higher educational levels [17.5%]

The education level of a person filing a compensation claim may alert an examiner in detecting pseudohypacusis

Persian competing word test: Development and preliminary results in normal children

Assessment of central auditory processing skills needs various behavioral tests in format of a test battery. There is a few Persian speech tests for documenting central auditory processing disorders. The purpose of this study was developing a dichotic test formed of one-syllabic words suitable for evaluation of central auditory processing in Persian language children and reporting its preliminary results in a group of normal children. Persian words in competing manner test was developed utilizing most frequent monosyllabic words in children storybooks reported in the previous researches. The test was performed at MCL on forty-five normal children [39 right-handed and 6 left-handed] aged 5-11 years. The children did not show any obvious problem in hearing, speech, language and learning. Free [n = 28] and directed listening [n = 17] tasks were investigated. The results show that in directed listening task, there is significant advantage for performance of pre-cued ear relative to opposite side. Right ear advantage is evident in free recall condition. Average performance of the children in directed recall is significantly better than free recall. Average row score of the test increases with the children age. Persian words in competing manner test as a dichotic test, can show major characteristics of dichotic listening and effect of maturation of central auditory system on it in normal children