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At least 19 recordsLinked to original sources
PubMed1978

[The effect of noise trauma on speech discrimination in silence and under influence of party noise (author's transl)].

Speech audiometry investigations were carried out in silence and under action of cocktail party noise in 44 soldiers. The testing subjects were grouped according to age and degree of noise lesion. The statistical evaluation of discrimination losses measured in silence and under acting party noise indicated that noise lesions induced considerable discrimination losses even in young subjects particularly under cocktail party noise conditions. Discrimination decreases significantly as the degree of noise trauma increases. In order to assess the real effect of the hearing loss caused by noise trauma upon speech discrimination, the tests of speech audiometry should be performed under noise conditions.

Adult↗
PubMed1979

Noise-induced hearing loss and the comprehension of speech in noise.

Subjects suffering from noise-induced hearing loss (NIHL) with or without hearing loss at 2 kHz were examined by speech audiometry with a three-digit test, bisyllabic and monosyllabic PB word lists in silence, and in USASI noise with a masking effect of 44 dB and 68 dB at 1 kHz. Subjects with up to 20 dB hearing loss at 2 kHz had almost the same speech comprehension in noise as normal hearing subjects. Subjects with hearing loss greater than 20 dB at 2 kHz had increasing discrimination loss at increasing noise levels. They also needed a signal-to-noise ratio better than normal-hearing persons would yield at the noise levels used. The evaluation of hearing disablement in occupational noise-included hearing loss should therefore be based for one-half on the results of speech audiometry in silence, and for the other half, in noise.

Adult↗
PubMed1975

[Noise level measurements of the air noise during drilling and grinding on the fresh isolated temporal bone (author's transl)].

Aerial sound measurements with different drilling instruments were performed during dry running and preparations of the bone. Registered were the values of the small drilling instruments Sirona, Dentatus-Air, and Electro-Torque-Ritter. Also tested were the KaVo-Technique-machine, the Hall-machine, the Air-Orbit-turbine, and the Sirona-turbine. During dry running most of them already reached the allowed marginal value of noise nuisance for the ear of 85 dB (A) at a distance of 35 cm. Only the Air-Orbit-machine showed a slightly lower value of 80 dB (A). The level increases with the used handpieces. Normal handpieces 1:1 exert only a minimal influence, gear handpieces 2:1, however, markedly increase the level. The verticity is of no importance in the range of normal rotations between 10,000 r/min. and 80,000 r/min. Only rotations in the lower frequency range of 2,000 r/min. markedly decrease the noise level. During bone drilling, the kind and size of the drilling bit have an influence on the intensity of the noise level. Quadruple wing milling cutters create a very high noise level (at a distance of 15 cm still above 110 dB [A!]), big rose cutters (R 16) create noise levels of 95 dB (A) and above, and only diamond round bits create less noise (approximately 88 db [A]). Small drilling bits make such a faint noise, that it is overroared by the drilling instrument. The turbines create only slightly higher levels than during dry running. Larger drilling bits cannot be employed here on principle. Wing milling cutters can lead to persistent damages of the inner ear. The frequent use of dental drilling instruments for bone preparations can also lead to a hearing loss of the operator in the long run.

Humans↗
PubMed1975

[The difference between the noise deafness of the pitmans and the typical noise-induced hearing loss of the worker in metals (author's transl)].

Reffering to 92 expert evidences on the noise-deafness the signs are shown, in which the mining noise-deafness differs from the typical noise deafness in the metallurgical industry. In more than 80% of the cases a slope of the curve could be observed in the audiogram beginning at 125 cps. Therefore the hearing loss early impairs the ability to understand conversational speech. Only every second patient shows a positive result at the SISI-test; this is the reason, that the mining noise deafness frequently is misinterpreted. In these cases the cochlear hearing loss will be surely proved by the Langenbeck-audiogram and Békésy-audiogram. A secondary finding was the typical "mining ear-drum". These ear drums are bilaterally whitish, without reflex and thickened; they don't show any air-bone gap in the audiogram. The differences between the mining noise-deafness and the typical noise-induced hearing loss are explained by an additional baro-trauma which occurs, when the pitmans work at a depth of about 2000 feet.

Audiometry↗
PubMed1976

[Effect of noise on the physiological functions in fowl. 2. Adaptation to noise of white leghorns and broilers].

Two experimental groups and series were compared (leghorns and broilers as well as two age groups of broilers) for their adaptive responses to repeated noise application. The noise was 100 dB and applied daily 30 minutes. The reference for comparison was the plasma-11-hydroxycorticosteroid concentration (11-OHKS). The results differed somewhat from those obtained earlier from one first short-time noise application, in that the rise in plasma glucocorticosteroid concentrations dropped from 431 to 210 per cent of the initial values in adult leghorns exposed to repeated noise stress over seven days. Adult broilers, however, did not exhibit any difference in the magnitude of rise of 11-OHKS concentrations by comparison between first and seven days of repeated stress. The initial values, however, were reached earlier by repeated noise application.

11-Hydroxycorticosteroids↗
PubMed1979

[Behaviour of the fast brain stem response P6 under noise influence, an "objective noise audiometry" (author's transl)].

The fast brain stem response can be recorded even at the threshold; it informs on hearing in the high frequency range of greater than or equal to 2000 cps. Especially in those frequencies often the differentiation between sensorial and neural hearing impairment is of interest--f. e. controlling the pure tone threshold in noise: at sensorial hearing loss tones remain heard within noise of equal loudness unaltered, at neural hearing loss the tone vanishes in noise, e. g. the tone-intensity must be increased to make the tone arise again. This phenomenon known from subjective audiometry mentally can be transferred to the recording of acoustic evoked potentials and can be proved by the behaviour of latency of P6: at sensorial hearing loss the latency is prolonged (corresponding to minus 20 dB) but the response furthermore is recorded in the noise as well as at the click masked threshold; at neural hearing loss, however, the response can be recorded again with a click-intensity, which exceeds that of the noise clearly.

Audiometry↗
PubMed1979

Current noise parameters derived from voltage noise and impedance in embryonic heart cell aggregates.

We have recorded membrane impedance and voltage noise in the pacemaker range of potentials (-70 to -59 mV) from spheroidal aggregates of 7-d embryonic chick ventricle cells made quiescent by exposure to tetrodotoxin in medium containing 4.5 mM K+. The input capacitance is proportional to aggregate volume and therefore to total membrane area. The specific membrane capacitance is 1.24 microF/cm2. The input resistance at constant potential is inversely proportional to aggregate volume and therefore to total membrane area. The specific membrane resistance in 18 k omega . cm2 at -70 mV and increases to 81 k omega . cm2 at -59 mV. The RC time constant is 22 ms at -70 mV and increases to 146 ms at -59 mV. The aggregate transmembrane small-signal impedance can be represented by a parallel RC circuit itself in parallel with an inductive branch consisting of a resistor (rL) and an inductor (L) in series. The time constant of the inductive branch (L/rL) is 340 ms, and is only weakly dependent on potential. Correlation functions of aggregate voltage noise and the impedance data were modeled by a population of channels with simple open-close kinetics. The time constant of a channel (tau s) derived from the noise analysis is 300 ms. The low frequency limit of the pacemaker current noise (SI[0]), derived from the voltage noise and impedance, increases from 10(-20) A2/Hz . cm2 at -67 mV to 10(-19) A2/Hz . cm2 at -61 mV.

Animals↗
PubMed1978

Psychophysiological reactions to noise as modified by personal control over noise intensity.

Effects of personal control over noise intensity were studied in experimental situations where subjects performed mental arithmetic under noise exposure. Every other subject was offered a choice between noise intensities, and the next subject, serving as his yoked partner, had to submit to the same noise. Mean measures of catecholamine and cortisol excretion, and of heart rate and subjective effort and discomfort showed that subjects were more aroused in the yoked situation. There were, however, considerable interindividual differences, subjects classified as 'internals' or 'externals' on the basis of the Internal-External Locus of Control Scale responding to the two experimental conditions in congruence with their general beliefs and attitudes with regard to control.

Adult↗
PubMed1977

Noise, discomfort and mental health. A review of the socio-medical implications of disturbance by noise.

The published work relating to effects of noice on man and animals is reviewed from the standpoint of mental health. Evidence from a number of different disciplines shows that the presence of meaning in the noise is of critical importance in determining the persistence of physical reactions to the noise. The existing evidence linking noise with mental illness is found to be unsatisfactory. The concept of annoyance and the relevance of noise annoyance to mental illness are discussed. Some specific suggestions for further work are put forward.

Adolescent↗
PubMed1979

The effect of masking by noise on word discrimination scores in listeners with normal hearing and with noise-induced hearing loss.

Patients with high-frequency hearing loss often complain at the Workers' Compensation Board that they find it difficult to hear speech in a noisy environment. This study was undertaken to test the validity of their complaints. The experiment had a 2x3x3 factorial design. The factors were subject group (normal hearing versus sensorineural hearing loss), stimulus level (65, 75, and 85 dB SPL), and speech-to-noise ratio (5, 12, and 19 dB). There were 6 subjects in each condition. Each subject was tested for his speech discrimination with three CID W-22 50-word lists, one in each of the three different speech-to-noise ratios. Both speech and pink noise were presented through loudspeakers in a sound field. The results support the patients' complaints. Possible explanations for the results are discussed.

Adult↗
PubMed1976

[Effect of noise on the physiological functions in fowl. 1. Effect of primary strong noise on the 11-OHKS level in broilers and leghorns].

The effects of first noises on broilers and white leghorns were tested by plasma levels on 11-hydroxycorticosteroid (11-OHKS). The noises were 100 dB, 60 to 8,00 Hz, and applied 30 minutss to one group of broilers, aged 14, 28, and 56 days, and to another group of broilers and white leghorns in adult age. The reactions were compared. Acoustic stimulation was followed by temporary activation of the hypothalamic pituitary-suprarenal system. The rise of the plasma glucocorticosteroid level in leghorns was three times as high as that in adult broilers, which was interpreted as a reflection of stronger organic stress. Reactions differed in intensity, depending on age as well. Plasma-11-OHKS levels went up by 32 per cent maximum in broilers aged 56 days or by 73 per cent in animals aged 14 days or 120 per cent in those aged 28 days. The above results seemed to support the conclusion that noises of the above quantity and quality represented stress on fowl.

11-Hydroxycorticosteroids↗
PubMed1978

[Noise-induced hearing loss and the sisi test. on the assessment of noise-induced hearing loss (author's transl)].

In the assessment of noise-induced hearing loss problems arise mainly in those cases where the middle frequencies are involved in the hearing defects at a proportionally high degree, because this strongly impairs the speech discrimination and because such a hearing defect cannot be regarded as a typical case of noise-induced hearing loss. A recruitment test must be carried out in the middle or lower frequency range in order to diagnose any possible multifactorial genesis of the hearing defect. As concerns the widely used SISI test the result is shown to depend not only on the test intensity but also on the test frequency. Since the hearing threshold in the middle under discussion is usually better in the middle and lower frequency ranges than in the higher ones and since, as a consequence, the test intensity in the SISI test is lower, frequently lower SISI values can be observed here than in the case of higher frequencies. Since the test of the lower frequencies results in lower SISI values than for higher frequencies also in those cases where the hearing threshold in the lower frequency range is the same or even worse, we must assume that the results of the SISI test depend on the frequency. In the examination of patients with a hearing defect where the hearing threshold curve flattens obliquely, intensity dependence and frequency dependence are added in the lower frequency range; negative SISI values are not infrequent. It is not admissible to conclude from that a retrocochlear defect in the middle and lower frequency ranges in cases of noise-induced hearing loss in the high-tone range.

Audiometry↗
PubMed1979

Noise-noise effect upon the spreading of the posttraumatic progressive necrosis in the organ of Corti.

Progressive necrosis of the organ of Corti caused by a disturbance of the ionic composition of the Cortilymph resulting from the infiltration of endolymph into the organi of Corti after traumatization of its barrier against the scala media, is greatly intensified by posttraumatic stimulation with noise of physiological intensities. This effect is attributed to oscillation of the cochlear partition, with resultant greater blending of the Cortilymph and the endolymph. Stimulation augments necrosis fourfold towards the base of the cochlea and twofold towards the helicotrema. Posttraumatic stimulation is one of the factors which markedly potentiate the regressive effect of acoustic trauma.

Acoustic Stimulation↗
PubMed1976

[Experiments on the medicamental treatment of the noise-induced cochlear damage. Part I. The effect of dipyridamol and allopurinol on the RMP of the cochlea (guinea pig) after noise (author's transl)].

Dipyridamol has in addition to a coronardilatating effect an ati-thrombotic one too. Moreover it facilitates the release of O2 from haemoglobin by increase of the concentration of 2,3-diphosphoglycerate in the erythrocytes. Allopurinol causes a potential resynthesis of ATP in the cells by inhibition of the metabolism of uric acid. Both substances therefore seemed to be suitable for a medicamental therapy of the noise-induced cochlear damage. The expected favourable effect of Dipyridamol and Allopurinol on the organ of Corti after sound exposure (RMP-measurement before and after exposure to pure tone 120 dB SPL) however had not been confirmed by experiment on animals (guinea pig).

Allopurinol↗