[Analysis of hearing aids application in elderly patients.]

The aim of the study is to evaluate the possibility to implement machine learning to create a digital auditory profile for elderly patients and to analyze the hearing aid fitting efficacy depending on involvement of the peripheral and central auditory pathways in a pathological process. Data analysis of 375 people aged 60-93 years is presented. 355 patients with chronic bilateral hearing loss (230 of them used hearing aids) were included in the main group, and 20 normal hearing elderly people were included in the control group. Audiological examination consisted of standard tests (pure tone audiometry, impedancemetry, speech audiometry in quiet) and tests to evaluate the central auditory processing (binaural fusion, dichotic digits, speech audiometry in noise, random gap detection). The Montreal Cognitive Assessment was used to detect cognitive impairment. The hearing aid fitting efficiency was evaluated with COSI questionnaire and speech audiometry in free field. Processing of the results was carried out using Pearson's correlation analysis aimed at creating a polynomial model of a patient's hearing on the basis of the limited test battery. There were close correlations between the state of cognitive functions and age, results of tests to evaluate the central auditory processing, as well as patients' satisfaction of hearing aid. The results of the work indicate the possibility of using computer technologies of data analysis to develop rehabilitation programs for elderly hearing impaired patients.

[Strategies of hearing aids fitting for improving speech recognition in noisy environments]. / Vozmozhnosti uluchsheniya razborchivosti rechi v shume pri slukhoprotezirovanii.

THE AIM OF THE STUDY: To assess speech recognition in users of mono- and binaural hearing aids (HA) with dynamic environment control system (DECS). MATERIAL AND METHODS: 25 HA users with symmetrical bilateral moderate to severe sensorineural hearing loss and 10 individuals with normal hearing underwent speech audiometry in a free sound field by listening to an adaptive Russian matrix sentence test with a background noise. The testing was conducted for hearing impaired patients with one and two HA. The Speech Recognition Thresholds in noise (SRTN) using HA with DESC and using HA without DESC were compared. The dichotic digits test and the rapidly alternating speech perception test were performed to evaluate the central auditory system function. RESULTS: The SRTN in normal hearing listeners was -16.4±1.9 dB SNR. In the case of monaural using HA without DESC the SRTN was -2.5±4.4 dB SNR, using HA with DESC it was -5.8±4.0 dB SNR; in the case of using binaural HAs it was -6.3±3.8 dB SNR and -9.9±3.1 dB SNR accordingly. CONCLUSIONS: HAs with Dynamic Environment Control System are highly effective for speech perception in noisy environments. Binaural HA use is more effective than monaural HA use regardless of HA model. Speech recognition in noisy environments in cases of binaural HA use correlates significantly with results of tests assessing the central auditory system function.

[The influence of central auditory processing on the intelligibility of the speech in the patients presenting with hearing impairment]. / Vliianie tsentral'nykh slukhovykh rasstroistv na razborchivost' rechi pri sensonevral'noi tugoukhosti.

The objective of the present study was to evaluate to what degree the function of the central auditory pathways influences the intelligibility of the speech in the patients suffering from the sensorineural loss of hearing (SNLH). The study included a total of 20 patients at the age varying from 31 to 80 years presenting with moderate to moderately severe symmetrical SNLN. All the patients were permanent hearing aid users. They underwent the standard audiological examination including pure-tone threshold and suprathreshold audimetries together with impedancemetry, the evaluation of the functional ability of the central auditory pathways with special reference to temporal resolution and differential frequency sensitivity, binaural integration, and the ability to distinguish a sound stimulus against the background noise. It has been found that the impaired intelligibility of the speech and the decreased efficiency of the hearing aids in the patients presenting with SNLH were attributable to the central auditory pathway disorders detected in 50% of the participants in the study. The strong correlation between the results of detection of the stimulus under conditions of tonal signal interference, the binaural integration test, and intelligibility of the speech in the users of hearing aids was documented.

[Rehabilitation of hearing impaired elderly patients by means of hearing aids with frequency lowering technology.]

The objective of this study was to assess the effectiveness of rehabilitation of hearing impaired elderly patients using hearing aids with frequency lowering technology called Frequency Composition ™. 23 hearing aid users (mean age 64 years) with moderate to severe sensorineural hearing loss were tested. All participants were divided into two groups according to configuration of audiogram: 11 people with averaged slope of 27,9 dB per an octave within frequency range of 1-2 kHz (the 1st group) and 12 people with slope of 24,1 dB at 2-4 kHz (the 2nd group). Average speech tests scores of the 1st group were significantly worse than for the 2nd group (p<0,05 in quiet; p<0,01 in noise). It has been seen that the 1st group had significant better improvement of speech understanding using of Frequency Composition™ than the 2nd group. It has been shown that frequency lowering can improve perception of high frequency sounds and enhance speech intelligibility especially in patients with audiogram slope within frequency range of 1-2 kHz. To effective use of frequency lowering technology a careful selection of patients and adaptation to the new algorithm of amplification are required.

[Peculiarities of hearing prosthetics for the patients suffering tympanophonia].

The objective of the present study was to estimate the influence of fractal tones (ZEN program) on chronic subjective tympanophonia in the patients using hearing aid apparatuses. A total of 20 subjects at the age from 30 to 69 years suffering tympanophonia in combination with grade I-IV loss of hearing were available for examination with the use of the following methods: analysis of complaints and medical histories, evaluation of ENT functioning, impedancometry, tonal threshold, suprathreshold and speech audiometry, psychoacoustic noise measurement, analysis of THI and TRQ questionnaires. The results of the questionnaire studies show that the use of the ZEN program and hearing aid apparatuses (Mind 440, WIDEX) decreased the intensity of tympanophonia in 90% of the patients. The therapeutic effect of the ZEN program in the younger patients was higher than in the elder ones. The probability of positive action of fractal tones decreased with increasing scores when the assessment was based on the primary THI and TRQ questionnaires.

[Alternating signal speech audiometry in the diagnosis of central lesions of the acoustic analyzer]. / Audiometriia chereduiushchimisia rechevymi signalami v diagnostike tsentral'nykh porazhenii slukhovogo analizatora.

Diagnostic sensitivity was compared for two binaural methods of "sensitized" speech audiometry--alternating speech audiometry (ASA) and Dichotic. A total of 35 patients were examined having neurosensory hypoacusis resultant from cerebrovascular atherosclerosis and chronic insufficiency of cerebral circulation. ASA indicated defects of the central parts of the acoustic analyzer in 80% of the examinees. The results of the two methods were similar in 85.7% of the patients. The diotic and dichotic alternating speech tests can be used separately and in combination in diagnosis of central acoustic disturbances, of vascular genesis, in particular.

[Function of acoustic analyzer in multiple sclerosis in exacerbation]. / Sostoianie funktsii slukhovogo analizatora pri rasseiannom skleroze v stadii obostreniia.

Audiometric examination of 51 patients with aggravated multiple sclerosis included pure-tone threshold audiometry, assessment, of speech intensity function, of adaptation, masking, sound laterality, impedance tympanomanometry, perception of complicated speech, registration of short-latency acoustic evoked potentials. Acoustic analyzer disfunction, especially that of sound laterality, was discovered in 42-83% and 68% of patients, respectively. The hearing system was affected most frequently at the level of brain stem and occasionally at the level of the cochlea (15%). Sorption detoxication therapy produced response in 100% of patients by subjective and neurological criteria, while only in 59% by acoustic criteria. This disagreement is likely to reflect subclinical symptoms and may represent a prognostic value.

Responses of yeast cells to heat applied alone or combined with gamma-rays.

Experiments were carried out to determine the effects of hyperthermia alone or combined with gamma-rays on the survival of yeast cells of different species. Arrhenius plots for the heat inactivation of yeast cells show inflection points. This suggests that hyperthermic killing above or below these temperatures is mediated by different mechanisms. The synergism between hyperthermia and ionizing radiation was almost linearly dependent on temperature as shown by Arrhenius plots for the combined action of both modalities. The data obtained may imply that different processes are involved in heat inactivation and thermal enhancement of yeast cell radiosensitivity.

[Effect on cell genotype on thermal radiosensitization of yeast]. / Vliianie genotipa kletok na teplovuiu radiosensibilizatsiiu drozhzhei.

The combined action of hyperthermia and ionizing radiation on the arrival of isogenic haploid and diploid yeast cells of wild type and rad51 mutant was studied. The experiments demonstrated the essential enhancement of radiosensitivity of diploid wild type cells is hyperthermic conditions. For haploid wild type cells and rad51 mutant cells the enhancement was smaller and negligible respectively. The action of both factors on rad51 homozygous diploid cells was additive. It is established that diploid cells were less thermosensitive than haploid ones. Rad51 mutation does not change these properties. It was concluded that the enhancement of radiosensitivity of cells under hyperthermic conditions depends on cell genotype and may be caused by the reduced capacity of cells to recover the radiation damages inflicted by the both modalities.

Effect of elevated temperatures on the radiation sensitivity of yeast cells of different species.

The influence of hyperthermia on the survival of irradiated yeast cells of different species has been studied. The experiments reported in the paper have shown: (1) simultaneous action of ionizing radiation and high temperatures appeared to increase the radiation response by a factor of approximately 2.7 for diploid and only by a factor of 1.5 for haploid cells of wild-type; (2) the combined action of high temperature and ionizing radiation had no synergistic effect for rad51 mutant diploid yeast cells; (3) heating before or after irradiation did not alter the radiation response of yeast cells; (4) enhancement of yeast cell sensitivity by simultaneous action of hyperthermia and 239Pu-alpha-particles was negligible; (5) the magnitude and the rate of liquid holding recovery is lowered with increasing of irradiation temperature. On this basis, it was concluded that possible mechanism for thermal sensitization of yeast cells may involve the reduced capacity of cells to recover damages resulted from the combined action of both modalities.