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.
Hearing Aids* ; Hearing Loss ; Hearing* ; Humans ; Noise* ; Rehabilitation ; Signal Processing, Computer-Assisted

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.

OBJECTIVE: Concerns about the safety of assisted reproductive technology (ART) have been raised, as some studies have shown elevated incidence rates of childhood cancer, asthma, allergies, and other diseases in ART-conceived babies. Findings regarding the health of ART-conceived babies are controversial. The present study was conducted to evaluate the prooxidant-antioxidant balance (PAB) in in vitro fertilization (IVF)-conceived mice in comparison to naturally conceived offspring. METHODS: Mice (6–8 weeks) were divided into two groups (IVF-conceived and naturally conceived) matched by sex, age, weight, and litter size. A 1-mL blood sample was taken and the sera were separated. The oxidant-antioxidant balance was evaluated using a fast and reliable PAB assay. The results were expressed as mean±standard deviation. RESULTS: The mean PAB values (HK units) in the IVF-conceived and naturally conceived groups were 59.70±22.30 and 54.70±18.22, respectively (p=0.82). CONCLUSION: Since free radicals contribute to several pathological conditions and antioxidants play an important protective role against oxidative stress, evaluating the oxidant-antioxidant balance is very important. Although the results of this study showed that the quality of the defense mechanism against free radicals was not significantly different between the IVF-conceived and naturally conceived mice, other parameters of metabolic dysfunction need to be measured.
Animals ; Antioxidants ; Asthma ; Fertilization in Vitro ; Free Radicals ; Hypersensitivity ; In Vitro Techniques* ; Incidence ; Litter Size ; Mice* ; Oxidative Stress ; Reproductive Techniques, Assisted

Objective: To identify the anti-Toxoplasma antibodies from blood donors who referred to blood transfusion bases of Jahrom County, using ELISA method. Methods: Based on the prevalence and characteristics method, 400 serum samples were collected from blood donors referred to Jahrom blood transfusion bases, Southern Iran, during 2010-2011, designed at testing by ELISA. IgM and IgG antibodies against Toxoplasma gondii were tested using ELISA kits (Dia-Pro) on serums. The data were analysed by SPSS 19 software. Results: Review of 400 cases, 54 of them were IgG positive for parasites (13.5%) and 346 of those with negative IgG (86.5%). In IgM examination, 1.75% of them have been positive IgM (7 cases) and 98.25% of them were IgM negative (393 cases). By comparing the different group ages, 40-50 year age group had the highest prevalence of IgG positive (17.9%) and the age group of 30-40 years had the highest incidence of IgM negative (2.5%). Conclusions: Due to the serological infection rate of toxoplasmosis obtained from this study, toxoplasmosis should be considered as a significant transfusion risk factor in Jahrom and also in any region with similar situations.