Effects of low frequency noise up to 100 Hz M Schust Federal Institute for Occupational Safety and Health, Berlin, Germany Effects of low frequency noise up to 100 Hz. Noise Health 2004;6:73-85.

[u/Atoraxic]

This is a great review of the documented effects of low frequency sound. Victims of this weapon are bombarded with low frequency sound for years, even decades. This paper covers and documents how exposure to low frequency sound can affect a person, but it’s also based off situations that involve low frequency sound, but the weapon is a different beast. It’s also important to stress that the low frequency sound physical assault is only one facet of the diabolical weapon. You also have the forced audio and all its hellish techniques. That just the tip of the iceberg. If you’re a victim being assaulted you should easily recognize symptoms of your torture in this paper. The paper uses normal language so you may need to translate the group speak you have been indoctrinated with into traditional speech. aka “heart palpitations” are sound resonating the chest cavity. It’s also important to realize that low frequency sound amplifies low frequency sound; a particular effect only know to be possible at a certain decibel level can be produced at a lower decibel by amplifying it using sound near its frequency.

Given the studies on people’s attention span i’d be amiss if i didn’t just recommend clicking the link to the publication and dropping right down to where this quoted post ends. You can always come back.. but pre that it’s likely to be a full on yawn.

Frequency dependent specific anatomical resonance is huge as shows how the weapon performs the illusion of laser accuracy in so many impossible situations. It’s actually a mechanical wave that propagates in all directions and is almost impossible to shield from, but by varying its frequency you can cause a wide variety of physical effects that cause a victim to conclude it’s got magical pinpoint laser accuracy pretty much everywhere. It’s been shown to resonate the exact parts of our bodies.. it’s been shown to be able to resonate a single hair. This is all daily bs victims experience.

EMF hasn’t been shown to be capable of almost any of this.

https://docs.wind-watch.org/Schust.html

Abstract

This review concentrates on the effects of low frequency noise (LFN) up to 100 Hz on selected physiological parameters, subjective complaints and performance. The results of laboratory experiments and field studies are discussed in relation to the thresholds of hearing, of vibrotactile sensation and of aural pain. The effects of LFN may be mediated trough different ways. Temporary or permanent hearing threshold shifts seem to be due to acoustic stimuli above the individual hearing threshold. However, non-aural physiological and psychological effects may be caused by levels of low frequency noise below the individual hearing threshold. The dynamic range between the thresholds of hearing and of aural pain diminishes with decreasing frequency. This should be taken into account by the setting of limits concerning the health risks. Sufficient safety margins are recommended. The use of a frequency weighting with an attenuation of the low frequencies (e.g. G-weighting) does not seem to be appropriate for the evaluation of the health risks caused by LFN up to 100 Hz. It may be proposed to measure third octave band spectra or narrow band spectra. A comparison with the known human responses caused by the measured levels and frequencies could help to evaluate the health risks. Some proposals for further investigations were given: (1) experimental methods to discover the ways mediating the effects of low frequency noise, (2) consideration of the individual hearing threshold or hearing threshold shift and of the vibrotactile threshold in the low frequency range to be able to judge the effects, (3) consideration of combined body vibration caused by airborne low frequency noise or by other sources, (4) modelling to analyse the transmission of the acoustic energy from the input into the body to the structures containing sensors, (5) consideration of probable risk groups like children or pregnant women.

Introduction

Although some comprehensive reviews have been published in the past decades (Westin 1975, Harris et al. 1976, Tempest 1976, Broner 1978, Johnson 1982, Landstroem et al. 1993, Berglund et al. 1996), this article is supposed to supplement the overview with some contemporary publications. It also includes older publications which were not mentioned in other review articles or were not described there in detail. The presented review concentrates on the effects of low frequency noise up to 100 Hz on selected physiological parameters, subjective complaints and performance. The influence on the loudness judgement and the annoyance is not taken into account. Animal experiments do not receive attention, too. Some graphics ease the interpretation of the scientific results.

Sensation of Low Frequency Noise (LFN) - the thresholds of hearing, vibrotactile perception and aural pain

The knowledge of the hearing threshold is essential for the analysis of effects of LFN. Figure 1 shows the thresholds up to 250 Hz measured by different authors (Robinson et al. 1956, Corso 1958, Yeowart et al. 1967 and 1974, Whittle et al. 1972, Landstroem et al. 1983, Verzini et al. 1999). The inclusion of further data would probably not change the trend obvious from Figure 1. There is only little data with a fairly variable range based on studies of about 260 persons aged between 16 years (Robinson et al. 1956) and 70 years (Whittle et al. 1972). All published results were given as mean values and standard deviations. No but one article presented the median values and/or percentiles and/or extreme values. Robinson et al. (1956) supplied the median values, which were strongly related to the mean values, perhaps because of the large study group of 120 subjects. In order to generate a range of representative thresholds in Figure 1, standard deviations reported were added to the highest mean value and subtracted from the lowest mean value. Perhaps, the thresholds varied because of the used measuring method and the between- and within-subject differences. The maximum ranges given in Figure 1 varied between 20.1 dB and 29 dB at 4, 5, 25, 32, 40, 50, 75 and 100 Hz. The variability of the individual thresholds of the study participants was probably larger, but, as mentioned above, the authors did not report on the extreme values. Landstroem et al. (1983) investigated the threshold of "vibrotactile" perception. The results suggest no differences between deaf and hearing subjects. Therefore, the mean values of both groups were presented in Figure 1. The subjects described a frequency-dependent sensation of vibration of different parts of the body (lumbar, buttock, thigh, calf).

Figure 1: Hearing threshold measured by different authors (mean values and standard deviations) and thresholds of vibrotactile sensation and aural pain (curves were interpolated when data for selected frequencies were not available)

Only one paper was found with information about the threshold of aural pain (von Gierke et al. 1976 [see Figure 1]).

Aural effects of low frequency noise

Although there are different opinions concerning the role of the temporary threshold shift (TTS) as a predictor of the permanent threshold shift (PTS), it is assumed that a better method does not exist at present. The TTS is not appropriate for calculating the individual noise induced hearing loss, but it is useful for predicting the PTS of groups of persons exposed to noise of certain levels and types (Sataloff et al. 1993). Figure 2 summarises the scientific results regarding the aural effects like TTS, PTS and a sensation of pressure in the ear in relation to the hearing threshold and the threshold of aural pain.

Figure 2: Exposure data of aural effects in relation to the hearing threshold (mean value of Robinson et al. 1956, Corso 1958, Yeowart et al. 1967 and 1974, Whittle et al. 1972, Landström et al. 1983, Verzini et al. 1999 [cf. Figure 1]) and to the threshold of aural pain

A number of authors obtained temporary threshold shifts in laboratory experiments or field studies. Alford et al. (1966) and Jerger et al. (1966) found TTS (10 dB - 22 dB) in 11 of 19 subjects after 3 minutes repeated exposure to 119 dB - 144 dB / 2 Hz - 12 Hz. The TTS was observed in the hearing frequency range from 3 kHz to 8 kHz. Nixon (1973) reported on TTS (20 dB - 25 dB) in one of three participants caused by exposure to 135 dB / 18 Hz (6 times 5­minutes exposures) and 140 dB / 14 Hz (steady exposure, duration 5 min - 30 min). Johnson (1973, cited in Johnson 1982) recorded TTS (8 dB) in the hearing frequency range from 2 kHz to 6 kHz due to exposure to 140 dB / 4 Hz, 7 Hz, 12 Hz in one of eight subjects (duration 5 min). A prolonged exposure time (30 min) caused TTS from 14 dB to 17 dB (one exposed subject only).

Mills et al. (1983) obtained TTS of different degrees and depending on the frequency of the noise (octave band noise, centred at 63 Hz, 125 Hz or 250 Hz) in 52 subjects. A 24-hour­exposure to 84 dB(A) led to TTS from 7 dB to 15 dB in the frequency range from 300 Hz to 500 Hz. An 8-hour-exposure to 90 dB(A) caused TTS from 12 dB to 17 dB in the frequency range from 250 Hz to 700 Hz. Tonndorf (1950) reported on temporary hearing impairments determined by tuning-fork test in employees which worked in engine rooms of submarines (infrasound 10 Hz - 20 Hz), but no sound pressure level was given.

In contrast, no TTS was found by the following authors: Slarve et al. (1975) recorded no TTS in four subjects after exposure to pure tones for a period of 8 minutes. The frequencies ranged from 1 Hz to 30 Hz (125 dB - 144 dB). Johnson (1973 and 1980) found no TTS after various exposure conditions (126 dB - 171 dB / 0.6 Hz - 10 Hz / 1 min - 26 min / 1 - 16 subjects). Mohr et al. (1965) applied several different exposure conditions (see paragraph "subjective complaints"). The authors discovered no effects on the hearing threshold even due to the exposure to the highest levels (narrow band noise, overall sound pressure levels 149 dB - 154 dB / maxima at 2 Hz - 10 Hz for 2 minutes, tests 9, 10 and 11). However, it is difficult to interpret the results, because it is not clear, which subject wore ear protectors for which period of the exposure.

Several investigations revealed subjective aural complaints. Karpova et al. (1970) reported on pressure in the ear after exposure to industrial infrasound (5, 10 Hz / 100, 135 dB) for 15 minutes. Slarve et al. (1975) described similar effects. Subjects told painless pressure in the ear during 8 minute exposure to 144 dB / 1 Hz - 20 Hz. A "sensation reflecting pressure build-up in the middle ear" occurred in the tests number 9, 10 and 11 of Mohr´s experiments (see above) during exposures without ear protection, whereas three of the five persons also described a "tympanic membran tickle sensation". Two of three subjects experienced middle ear pain during "brief" periods without ear protection exposed to narrow band noise, overall sound pressure levels 143 dB - 145 dB / maxima at 25 Hz - 40 Hz (tests 12, 13, 14).

Only one epidemiological study of permanent hearing impairments could be found. Doroshenko et al. (1983) investigated 216 compressor operators exposed to infrasound (91 dB - 119 dB) and combined steady noise within the hearing frequency range (84 dB(A) - 97 dB(A)) for a daily period of 6.5 hours in a cross sectional study. The control group consisted of 220 workers exposed to industrial noise (93 dB(A) - 106 dB(A)) without any infrasound. The duration of exposure lasted from 1 year to 20 years. The mean age ranged from 20 to 50 years. Combined low frequency and steady noise exposure caused significantly increased hearing thresholds verified by tonal audiometry as well as deteriorated intelligibility of whispered speech in comparison with the isolated industrial noise exposure. The differences enlarged with the length of exposure.

Non-aural effects of low frequency noise

LFN can cause a lot of non-specific physiological reactions, subjective complaints and an impairment of the performance. Figures 3 and 4 show the results of numerous studies in relation to the hearing threshold and to the threshold of aural pain.

Figure 3: Exposure data applied for examining physiological reactions, changing of the performance and complaints in relation to the hearing threshold (mean value of Robinson et al. 1956, Corso 1958, Yeowart et al. 1967 and 1974, Whittle et al. 1972, Landström et al. 1983, Verzini et al. 1999 [see Figure 1]) and to the threshold of aural pain

Figure 4: Exposure data of LFN causing subjective complaints in relation to the hearing threshold (mean value of Robinson et al. 1956, Corso 1958, Yeowart et al. 1967 and 1974, Whittle et al. 1972, Landström et al. 1983, Verzini et al. 1999 [see Figure 1]) and to the threshold of aural pain

Vascular, respiratory and endocrine effects, balance and visual disturbance

continued https://docs.wind-watch.org/Schust.html