AURORAL SOUNDS
2003
Tommi Gronlund, Petteri Nisunen & Foreign Office Architects
Tommi Gronlund, Petteri Nisunen:
Native people living in regions where aurora is common often claim that they hear rustling and crackling sounds coincident with their visual observations of northern lights. However, the scientists who tried to record and amplify these sounds in the 1960's continuously failed in their attempt. Aurora never gets closer to the earth than 80 km and there is no known physical mechanism that could transmit weak sound waves to the ground from this altitude.
One explanation for the sounds was, and for some still is, that the whole phenomenon is a psychological effect. If the brain does not get the response it is expecting it manufacturers one. People expect that the vivid auroral display should be accompanied by sound and their brain goes along with the expectation.
Tommi Gronlund, Petteri Nisunen:
Native people living in regions where aurora is common often claim that they hear rustling and crackling sounds coincident with their visual observations of northern lights. However, the scientists who tried to record and amplify these sounds in the 1960's continuously failed in their attempt. Aurora never gets closer to the earth than 80 km and there is no known physical mechanism that could transmit weak sound waves to the ground from this altitude.
One explanation for the sounds was, and for some still is, that the whole phenomenon is a psychological effect. If the brain does not get the response it is expecting it manufacturers one. People expect that the vivid auroral display should be accompanied by sound and their brain goes along with the expectation.
Other, more resent, explanations are based on the assumption that aurora can be "heard" through their changing magnetic properties.
The most popular mechanisms for the generation of auroral sound are coronal discharge and geophysical electrophonics.
According to the coronal discharge mechanism the production of auroral sound hinges on the coronal discharge, or ionization, of air occurring simultaneously with the aurora [Davis, 1992]. The rustling or hissing sounds result from the occurrence of a discharge from point electrodes where a very sharp potential gradient can exist [Silverman and Tuan, 1973]. The potential gradient is generated as the aurora perturbs the Eart's electric field. If this mechanism is the cause of auroral sound, auroral phenomena must create high electric fields (1500V/m) near the ground [Davis, 1992]. Although this mechanism can explain some of the higher frequency components of auroral sounds, the observations do not include the 'St.Elmo's Fire' effect which should be caused by it [Keay, 1990]. It also fails to account for the localization of the observations. Auroral sounds are often heard by only parts of groups of observers, not the complete group.
Geophysical electrophonics has been defined as the production of audible noises of various kinds through direct conversion by transduction of very low frequency electromagnetic energy generated by a number of geophysical phenomena. This mechanism proposes that auroral sounds are due to the ELF (extremely low frequency, 30 Hz to 3 kHz) and VLF (very low frequency, 3 kHz to 30 kHz) waves produced as the auroral particles stream towards the Earth. These waves, referred to as auroral hiss, immediately propagate to the ground where they may become transduced to sound waves. If the VLF amplitude is sufficient, the combination of high electric field modulated by a transduction process [Keay, 1990]. Davis [1992] suggests that the transduction process can be explained by the piezoelectric effect occurring on materials of the Earth's surface. A piezoelectric subjected to an electrical voltage expands or contracts and that motion might generate sound waves. The transduction may be clothing, glasses, loose hair or something very close to observer such that only that person hears the sounds or it may be by surrounding objects allowing a group of observers to hear the sounds [Keay, 1990].
We first got interested in auroral sounds after reading about the research made by a Finnish scientist Unto K. Laine. Depending on the source, he or Eigil Ungstrup from Denmark is claimed to be the first one to record these sounds with scientifically acceptable methods. We are not interested only in the phenomenon as such but also in the research methods used to study it. Besides recording and measuring these sounds with electronic devices in artic surroundings the scientist also collect descriptions of sounds from people who have heard them. We found Laine's guide book on how to sensitize ears to listen weak sounds especially interesting because it comes close to what we deal with in our own sound works. We wanted to take this phenomenon and its research as our starting point for the joint project with Foreign Office Architects although we do not know yet where, if anywhere, it will finally take us.
Foreign Office Architects:
The objective of our research is to explore distortion in sound experience through geometrical variation. Our aim is to produce an inhabited musical instrument with ice, using the high sound reflectivity of ice and the northern lights sounds collected by Tommi Gronlund and Petter Nisunen as the sound source. The building will be at the same time a loudspeaker and a distorter.
AURORAL SOUNDS
2003
Tommi Gronlund, Petteri Nisunen & Foreign Office Architects
Tommi Gronlund, Petteri Nisunen:
Native people living in regions where aurora is common often claim that they hear rustling and crackling sounds coincident with their visual observations of northern lights. However, the scientists who tried to record and amplify these sounds in the 1960's continuously failed in their attempt. Aurora never gets closer to the earth than 80 km and there is no known physical mechanism that could transmit weak sound waves to the ground from this altitude.
One explanation for the sounds was, and for some still is, that the whole phenomenon is a psychological effect. If the brain does not get the response it is expecting it manufacturers one. People expect that the vivid auroral display should be accompanied by sound and their brain goes along with the expectation.
Tommi Gronlund, Petteri Nisunen:
Native people living in regions where aurora is common often claim that they hear rustling and crackling sounds coincident with their visual observations of northern lights. However, the scientists who tried to record and amplify these sounds in the 1960's continuously failed in their attempt. Aurora never gets closer to the earth than 80 km and there is no known physical mechanism that could transmit weak sound waves to the ground from this altitude.
One explanation for the sounds was, and for some still is, that the whole phenomenon is a psychological effect. If the brain does not get the response it is expecting it manufacturers one. People expect that the vivid auroral display should be accompanied by sound and their brain goes along with the expectation.
Other, more resent, explanations are based on the assumption that aurora can be "heard" through their changing magnetic properties.
The most popular mechanisms for the generation of auroral sound are coronal discharge and geophysical electrophonics.
According to the coronal discharge mechanism the production of auroral sound hinges on the coronal discharge, or ionization, of air occurring simultaneously with the aurora [Davis, 1992]. The rustling or hissing sounds result from the occurrence of a discharge from point electrodes where a very sharp potential gradient can exist [Silverman and Tuan, 1973]. The potential gradient is generated as the aurora perturbs the Eart's electric field. If this mechanism is the cause of auroral sound, auroral phenomena must create high electric fields (1500V/m) near the ground [Davis, 1992]. Although this mechanism can explain some of the higher frequency components of auroral sounds, the observations do not include the 'St.Elmo's Fire' effect which should be caused by it [Keay, 1990]. It also fails to account for the localization of the observations. Auroral sounds are often heard by only parts of groups of observers, not the complete group.
Geophysical electrophonics has been defined as the production of audible noises of various kinds through direct conversion by transduction of very low frequency electromagnetic energy generated by a number of geophysical phenomena. This mechanism proposes that auroral sounds are due to the ELF (extremely low frequency, 30 Hz to 3 kHz) and VLF (very low frequency, 3 kHz to 30 kHz) waves produced as the auroral particles stream towards the Earth. These waves, referred to as auroral hiss, immediately propagate to the ground where they may become transduced to sound waves. If the VLF amplitude is sufficient, the combination of high electric field modulated by a transduction process [Keay, 1990]. Davis [1992] suggests that the transduction process can be explained by the piezoelectric effect occurring on materials of the Earth's surface. A piezoelectric subjected to an electrical voltage expands or contracts and that motion might generate sound waves. The transduction may be clothing, glasses, loose hair or something very close to observer such that only that person hears the sounds or it may be by surrounding objects allowing a group of observers to hear the sounds [Keay, 1990].
We first got interested in auroral sounds after reading about the research made by a Finnish scientist Unto K. Laine. Depending on the source, he or Eigil Ungstrup from Denmark is claimed to be the first one to record these sounds with scientifically acceptable methods. We are not interested only in the phenomenon as such but also in the research methods used to study it. Besides recording and measuring these sounds with electronic devices in artic surroundings the scientist also collect descriptions of sounds from people who have heard them. We found Laine's guide book on how to sensitize ears to listen weak sounds especially interesting because it comes close to what we deal with in our own sound works. We wanted to take this phenomenon and its research as our starting point for the joint project with Foreign Office Architects although we do not know yet where, if anywhere, it will finally take us.
Foreign Office Architects:
The objective of our research is to explore distortion in sound experience through geometrical variation. Our aim is to produce an inhabited musical instrument with ice, using the high sound reflectivity of ice and the northern lights sounds collected by Tommi Gronlund and Petter Nisunen as the sound source. The building will be at the same time a loudspeaker and a distorter.
AURORAL SOUNDS
2003
Tommi Gronlund, Petteri Nisunen & Foreign Office Architects
Tommi Gronlund, Petteri Nisunen:
Native people living in regions where aurora is common often claim that they hear rustling and crackling sounds coincident with their visual observations of northern lights. However, the scientists who tried to record and amplify these sounds in the 1960's continuously failed in their attempt. Aurora never gets closer to the earth than 80 km and there is no known physical mechanism that could transmit weak sound waves to the ground from this altitude.
One explanation for the sounds was, and for some still is, that the whole phenomenon is a psychological effect. If the brain does not get the response it is expecting it manufacturers one. People expect that the vivid auroral display should be accompanied by sound and their brain goes along with the expectation.
Tommi Gronlund, Petteri Nisunen:
Native people living in regions where aurora is common often claim that they hear rustling and crackling sounds coincident with their visual observations of northern lights. However, the scientists who tried to record and amplify these sounds in the 1960's continuously failed in their attempt. Aurora never gets closer to the earth than 80 km and there is no known physical mechanism that could transmit weak sound waves to the ground from this altitude.
One explanation for the sounds was, and for some still is, that the whole phenomenon is a psychological effect. If the brain does not get the response it is expecting it manufacturers one. People expect that the vivid auroral display should be accompanied by sound and their brain goes along with the expectation.
Other, more resent, explanations are based on the assumption that aurora can be "heard" through their changing magnetic properties.
The most popular mechanisms for the generation of auroral sound are coronal discharge and geophysical electrophonics.
According to the coronal discharge mechanism the production of auroral sound hinges on the coronal discharge, or ionization, of air occurring simultaneously with the aurora [Davis, 1992]. The rustling or hissing sounds result from the occurrence of a discharge from point electrodes where a very sharp potential gradient can exist [Silverman and Tuan, 1973]. The potential gradient is generated as the aurora perturbs the Eart's electric field. If this mechanism is the cause of auroral sound, auroral phenomena must create high electric fields (1500V/m) near the ground [Davis, 1992]. Although this mechanism can explain some of the higher frequency components of auroral sounds, the observations do not include the 'St.Elmo's Fire' effect which should be caused by it [Keay, 1990]. It also fails to account for the localization of the observations. Auroral sounds are often heard by only parts of groups of observers, not the complete group.
Geophysical electrophonics has been defined as the production of audible noises of various kinds through direct conversion by transduction of very low frequency electromagnetic energy generated by a number of geophysical phenomena. This mechanism proposes that auroral sounds are due to the ELF (extremely low frequency, 30 Hz to 3 kHz) and VLF (very low frequency, 3 kHz to 30 kHz) waves produced as the auroral particles stream towards the Earth. These waves, referred to as auroral hiss, immediately propagate to the ground where they may become transduced to sound waves. If the VLF amplitude is sufficient, the combination of high electric field modulated by a transduction process [Keay, 1990]. Davis [1992] suggests that the transduction process can be explained by the piezoelectric effect occurring on materials of the Earth's surface. A piezoelectric subjected to an electrical voltage expands or contracts and that motion might generate sound waves. The transduction may be clothing, glasses, loose hair or something very close to observer such that only that person hears the sounds or it may be by surrounding objects allowing a group of observers to hear the sounds [Keay, 1990].
We first got interested in auroral sounds after reading about the research made by a Finnish scientist Unto K. Laine. Depending on the source, he or Eigil Ungstrup from Denmark is claimed to be the first one to record these sounds with scientifically acceptable methods. We are not interested only in the phenomenon as such but also in the research methods used to study it. Besides recording and measuring these sounds with electronic devices in artic surroundings the scientist also collect descriptions of sounds from people who have heard them. We found Laine's guide book on how to sensitize ears to listen weak sounds especially interesting because it comes close to what we deal with in our own sound works. We wanted to take this phenomenon and its research as our starting point for the joint project with Foreign Office Architects although we do not know yet where, if anywhere, it will finally take us.
Foreign Office Architects:
The objective of our research is to explore distortion in sound experience through geometrical variation. Our aim is to produce an inhabited musical instrument with ice, using the high sound reflectivity of ice and the northern lights sounds collected by Tommi Gronlund and Petter Nisunen as the sound source. The building will be at the same time a loudspeaker and a distorter.
AURORAL SOUNDS
2003
Tommi Gronlund, Petteri Nisunen & Foreign Office Architects
Tommi Gronlund, Petteri Nisunen:
Native people living in regions where aurora is common often claim that they hear rustling and crackling sounds coincident with their visual observations of northern lights. However, the scientists who tried to record and amplify these sounds in the 1960's continuously failed in their attempt. Aurora never gets closer to the earth than 80 km and there is no known physical mechanism that could transmit weak sound waves to the ground from this altitude.
One explanation for the sounds was, and for some still is, that the whole phenomenon is a psychological effect. If the brain does not get the response it is expecting it manufacturers one. People expect that the vivid auroral display should be accompanied by sound and their brain goes along with the expectation.
Tommi Gronlund, Petteri Nisunen:
Native people living in regions where aurora is common often claim that they hear rustling and crackling sounds coincident with their visual observations of northern lights. However, the scientists who tried to record and amplify these sounds in the 1960's continuously failed in their attempt. Aurora never gets closer to the earth than 80 km and there is no known physical mechanism that could transmit weak sound waves to the ground from this altitude.
One explanation for the sounds was, and for some still is, that the whole phenomenon is a psychological effect. If the brain does not get the response it is expecting it manufacturers one. People expect that the vivid auroral display should be accompanied by sound and their brain goes along with the expectation.
Other, more resent, explanations are based on the assumption that aurora can be "heard" through their changing magnetic properties.
The most popular mechanisms for the generation of auroral sound are coronal discharge and geophysical electrophonics.
According to the coronal discharge mechanism the production of auroral sound hinges on the coronal discharge, or ionization, of air occurring simultaneously with the aurora [Davis, 1992]. The rustling or hissing sounds result from the occurrence of a discharge from point electrodes where a very sharp potential gradient can exist [Silverman and Tuan, 1973]. The potential gradient is generated as the aurora perturbs the Eart's electric field. If this mechanism is the cause of auroral sound, auroral phenomena must create high electric fields (1500V/m) near the ground [Davis, 1992]. Although this mechanism can explain some of the higher frequency components of auroral sounds, the observations do not include the 'St.Elmo's Fire' effect which should be caused by it [Keay, 1990]. It also fails to account for the localization of the observations. Auroral sounds are often heard by only parts of groups of observers, not the complete group.
Geophysical electrophonics has been defined as the production of audible noises of various kinds through direct conversion by transduction of very low frequency electromagnetic energy generated by a number of geophysical phenomena. This mechanism proposes that auroral sounds are due to the ELF (extremely low frequency, 30 Hz to 3 kHz) and VLF (very low frequency, 3 kHz to 30 kHz) waves produced as the auroral particles stream towards the Earth. These waves, referred to as auroral hiss, immediately propagate to the ground where they may become transduced to sound waves. If the VLF amplitude is sufficient, the combination of high electric field modulated by a transduction process [Keay, 1990]. Davis [1992] suggests that the transduction process can be explained by the piezoelectric effect occurring on materials of the Earth's surface. A piezoelectric subjected to an electrical voltage expands or contracts and that motion might generate sound waves. The transduction may be clothing, glasses, loose hair or something very close to observer such that only that person hears the sounds or it may be by surrounding objects allowing a group of observers to hear the sounds [Keay, 1990].
We first got interested in auroral sounds after reading about the research made by a Finnish scientist Unto K. Laine. Depending on the source, he or Eigil Ungstrup from Denmark is claimed to be the first one to record these sounds with scientifically acceptable methods. We are not interested only in the phenomenon as such but also in the research methods used to study it. Besides recording and measuring these sounds with electronic devices in artic surroundings the scientist also collect descriptions of sounds from people who have heard them. We found Laine's guide book on how to sensitize ears to listen weak sounds especially interesting because it comes close to what we deal with in our own sound works. We wanted to take this phenomenon and its research as our starting point for the joint project with Foreign Office Architects although we do not know yet where, if anywhere, it will finally take us.
Foreign Office Architects:
The objective of our research is to explore distortion in sound experience through geometrical variation. Our aim is to produce an inhabited musical instrument with ice, using the high sound reflectivity of ice and the northern lights sounds collected by Tommi Gronlund and Petter Nisunen as the sound source. The building will be at the same time a loudspeaker and a distorter.
ARTWORK
ARTWORK
ARTWORK
