Piotr skrev:Ragnwald skrev:Piotr skrev:Tror att neråt 16-17Hz kan upplevas som ton.
Vet att jag hörde 17Hz för några år sedan.
Nop, det är deltonerna i disten du hörde.
Trumhinnorna uppfattar lätt trycket, men hör du också ton, så är det även dist.
Det vet du ju inte om du inte har mer info om hur jag gjorde testen och med vad för utrustning.
Jag vet hur 34Hz och 51Hz låter och det är inte det jag skriver om. Jag skriver att jag uppfattar annat än bara "tryck" när jag lyssnar på sinus runt 17-20Hz. Jag uppfattar en ton.. något som ljuder. Ok?
Enligt vetenskapen hör människan (vid unga år) 20Hz-20kHz.. vad är det som får dig att tro att det inte finns individer som kan höra med större eller mindre utsträckning? Vidare har ju ljudstyrkan stor betydelse (needless to say).
/Peter
Från answers.com (referenser finns för den som vill läsa mer)
Human reactions to infrasound
Twenty Hz is considered the normal low frequency limit of human hearing. When pure sine waves are reproduced under ideal conditions and at very high volume, a human listener will be able to identify tones as low as 12 Hz.[15] Below 10 Hz it is possible to perceive the single cycles of the sound, along with a sensation of pressure at the eardrums.
The dynamic range of the auditory system decreases with decreasing frequency. This compression can be seen in the equal-loudness-level contours, and it implies that a slight increase in level can change the perceived loudness from barely audible to loud. Combined with the natural spread in thresholds within a population, it may have the effect that a very low frequency sound which is inaudible to some people may be loud to others.
Infrasound has been known to cause feelings of awe or fear in humans. Since it is not consciously perceived, it can make people feel vaguely that supernatural events are taking place.[16]
Some film soundtracks make use of infrasound to produce unease or disorientation in the audience. Irréversible is one such movie.
The infrasound and low-frequency noise produced by some wind turbines is believed to cause certain breathing and digestive problems in humans and other animals close to the turbines.[17]
Infrasonic 17 Hz tone experiment
On May 31, 2003, a team of UK researchers held a mass experiment where they exposed some 700 people to music laced with soft 17 Hz sine waves played at a level described as "near the edge of hearing", produced by an extra-long-stroke subwoofer mounted two-thirds of the way from the end of a seven-meter-long plastic sewer pipe. The experimental concert (entitled Infrasonic) took place in the Purcell Room over the course of two performances, each consisting of four musical pieces. Two of the pieces in each concert had 17 Hz tones played underneath. In the second concert, the pieces that were to carry a 17 Hz undertone were swapped so that test results would not focus on any specific musical piece. The participants were not told which pieces included the low-level 17 Hz near-infrasonic tone. The presence of the tone resulted in a significant number (22%) of respondents reporting anxiety, uneasiness, extreme sorrow, nervous feelings of revulsion or fear, chills down the spine and feelings of pressure on the chest.[18][19] In presenting the evidence to British Association for the Advancement of Science, Professor Richard Wiseman said, "These results suggest that low frequency sound can cause people to have unusual experiences even though they cannot consciously detect infrasound. Some scientists have suggested that this level of sound may be present at some allegedly haunted sites and so cause people to have odd sensations that they attribute to a ghost—our findings support these ideas."[16]
You are entitled to your own opinion. You are however not entitled to your own facts.
Ett sätt är ju att stega sig upp med en tongenerator på högsta volym som man dimentionerat för. Då brukar det ge sig tillkänna vad det är som låter.
