Aftershokz and other bone conduction sound devices
Hearing impairment is a big and important problem, which has been devoted to centuries of research, but at the same time almost every case has to be considered individually from a specific cause to a specific effect, of which there are countless. However, a couple of years ago, Google Glass “resurrected” the concept of bone conduction, and I would like to remind it very fluently today in connection with Aftershokz headphones.
I will begin with a picture in which our sound-conducting system is schematically depicted, and formally everything I need to know about it: I have three ears, an outer, middle and inner, and each of them is at risk. At the same time, according to statistics, neurosensory hearing loss, unfortunately, accounts for more than 70%, and therefore the problems of people with lesions of the external and middle ear for a long time were, as it were, on the 2nd plane.
Bone conduction apparatus
')
In most cases, when it comes to a hearing aid, a picture of an intra-ear or ear-ear device appears before your eyes, which converts an acoustic signal into an electrical one and vice versa, amplifying it. However, in some cases, the use of such a device is meaningless.
And if the sound-conducting system is impaired at the level of the external and middle ear, then physicians may recommend hearing aids with bone conduction. Of course, without consulting an audiologist and research on an audiometer, it is better not to test any devices on yourself! On a typical threshold audiogram, in this case there will be high thresholds for airborne sound and a normal perception of bone sounds, in contrast to neurosensory disorders. The Rinne test in the case of conductive hearing loss will be negative if the tuning fork is heard longer through the bone than “through the air”.
The technology of bone conduction of sound has been discovered long ago, Nobel Prizes have been obtained, and to understand that people with conductive hearing loss can live and work normally, you can remember Beethoven: he finished writing his quartets when he was seriously ill, and used wooden sticks between his teeth as a tool .
The book “Music and Medicine” by Dvoretsky clarifies that the disease that struck the composer was at first accompanied by the loss of high tones and the painful perception of loud sounds, but the bone conduction remained, so we now have the pleasure to listen to such music.
15th quartet of Beethoven, 1825. The composer is already seriously ill
The “dental method,” which the genius used, was later reviewed, described, and the outstanding scientist Bekesy later proved the regularity between the lower jaw and the bone conduction of sound, and nowadays such studies are carried out in the United States. In particular, the experiment described in the journal Special Care in Dentistry shows that among more than 1,000 patients, bone conduction was worse in people with fewer teeth. In total, 5, 3 percent took part in the experiment - they had no teeth; 15, 4 - had less than 17 teeth.
Diagnostics show that bone conduction devices can also be prescribed in such cases:
Bone devices convert sound into vibrations transmitted to the solid tissues of the skull, from where to the cochlea of ​​the inner ear.
In form, these hearing aids were different, and some sensors could even be located on the arms of the glasses, but all non-implantable devices could be accompanied by painful sensations due to the pressure that the headbands of such "gadgets" had.
Also, the disadvantage was:
Therefore, BAHA bone hearing aids have actually been a monopolist for a long time on the market, whose studies, in particular, in the journal Clinical Otolaryngology can be found since the mid-1990s.
They could be barely noticeable and almost did not give out health problems, but the process of “integration” of such a device was slow.
BAHA devices are multipart: processor, “adapter” and “pin”, which were implanted into the skull, which was possible due to the “livability” of bones and titanium, discovered by Professor Branemark.
At the same time, the integration of such hearing aids took place in two stages: the implantation of a titanium pin and six months later (during this time it grew together with a bone) “hanging” the processor.
There were complications! Infections could occur, hard tissues could be damaged, surrounding tissues could inflame and a pocket could appear that made the implant moveable, and among the most frequent were inflammation of the skin around the pin.
However, neither this nor the tests in medical journals stopped people. By the way, repeatedly repeated experiments did not convincingly prove the “super-ability” of BAHA and non-universality. This conclusion was made in 1999 in the same “Clinical Otolaryngology”, later, in our days, researchers JL Colquitt, E. Loveman, DM Baguley and others, referring to previous experience, told about the advantages of such devices in some cases ". Already in 2015, the journal Laryngoscope clarifies that despite the colossal previous experience, research is not enough, and they must continue.
Thus, if you look 10 or 15 years ago, the comparative table of hearing aids with bone conduction sound could be like that.
Similar to the BAHA principle, the more modern Alpha digital hearing aids work, they are also implantable, but they provide ample opportunities in terms of noise suppression, etc.
It should be added that as early as 1990 doctor GG Browning believed that implanted hearing aids with bone sound transmission might not be relevant for every bone conduction threshold.
Today's research, which has become more targeted, "sighting", considers all possible variants of dependencies and cause-effect relationships that can provoke hearing impairment. At the same time, despite the fact that the inner ear of a person turns out to be “less protected”, since it is formed first of all, on the 4th week of pregnancy, intrauterine deafness is manifested only in 13% of cases, and immediately after birth - in 59% of cases.
Modern researchers, for example, Pascal Dollé and Raymond Romand, in 2006 on the pages of the Journal of Neurobiology, clarified that in many respects the precursor of hearing impairment is the lack of retinol (Vit A) in the body, however, of course, the morphogenesis of the inner ear is affected not only by the lack of the right amount of a particular vitamin.
Also, the role of mutations of the GJB2 gene, which encodes the transmembrane protein connexin 26, which participates in the intercellular contacts in the tissues of the inner ear, is noted, but the frequency of congenital neurosensory hearing loss associated with this gene is 1: 1000 in newborns.
Gjb2
A special role for hearing problems is assigned in geriatrics. In a number of publications it is argued that such an obvious cause of hearing impairment, such as aging, does not allow many to come to terms with it in old age. Dr. Allan Sinclair, in his work, argues that this causes a much more serious problem: the elderly are depressed, and there are frequent cases of attempted suicide!
The fact that the problem is massive and global, can say, for example, such a collective work of doctors Adriaan Moelker, Ronald AJJ Maas, Mohamed Ouhlous. Their research is devoted to the influence of MRI devices on the human sound system. The study was conducted in 2005, 10 years ago.
Google handles
Interest in bone conduction with glasses Google was excited by a journalist who complained that the glasses are unsuitable for people with disabilities. At the same time, it seems he didn’t have to rely on anything because his auditory system had lesions in the inner ear, and therefore there was little bone conductivity could be useful to him.
Nevertheless, Google demonstrated this technology again and showed that now in some cases, it’s not enough that you don’t have to drill the skull and wait for half a year to “implant” the titanium, but you don’t have to pay 200,000 rubles for it Our money for the devices BAHA! On the other hand, not everyone was comfortable wearing glasses, and not everyone needed to, but small and proud Aftershokz, who at that time seemed to lack his authority to shout out loud, came to life. And a year later there was a real flourishing and hundreds of press references.
However, despite the fact that even the Aftershokz logo transparently hints at the hearing impaired, they have built an advertising campaign on a different strategy.
Aftershock in the press
In the international and domestic press, “Aftershokz” is increasingly featured as headphones for sports, according to the headlines in Mashable, “Los Angeles Times”, in English “Independent”, “techlicious”, “Men'sHealth” and private reviews.
There are reasons for this, and Aftershokz today is called headphones, safe for athletes, especially for cyclists: headphones do not cover their ears, and therefore a person can hear ambient sounds, car signals, etc.
This is supported by international statistics on the number of accidents involving cycling. In particular:
United Kingdom - 2013
In the United States in 2012 killed more than 700 cyclists.
Head injuries are among the most common fatal injuries.
During the same period, 271 road accidents involving a bicycle were shown in Moscow, in which 2 people died (1 child), 11 people were seriously injured (2 children).
In this sense, Aftershokz is an absolute breakthrough, because “shifting” the headphones above the ears and increasing the volume did not give such a perception, and plus to everything, there is a microphone in the headphones, so many simply use them as a means of communication.
Judging by the reviews, a certain vibration, which is logical for bone conduction devices, was haunted by many for some time, but got used to it very quickly. Or resigned.
My client
Unfortunately, today I have only a theoretical understanding that in some cases with hearing impairment, Aftershokz’s capabilities will be useful. The only clue now is the client's feedback, who took the headphones from us for his grandfathers.
I quote literally:
“With headphones everything is fine - the first tests went off with a bang. Without any additional devices, grandfathers without hearing aids can communicate tolerably by telephone, which is quite surprising for them. That is, we connect the headphones as a headset to the phone and everything - the grandfathers can talk on the phone and hear quite well. ”
And in the second letter:
“The most curious thing is that one of my grandfathers is almost completely deaf, hears only one ear, and even that is only 5-10% compared with a healthy person. But even he heard enough when we talked with him on the phone, which means that he can already walk with a mobile phone and answer if something happens, and in addition, at the same time he can wear his hearing aid.
The other grandfather hears much better, although much weaker than a healthy person. On the phone with him, however, I could not talk - he could not hear what I was saying to him, and yesterday I directly felt that he was hearing me well, almost like an ordinary person.
Ordinary headphones, worn on a hearing aid, did not give such hearing to any of my grandfathers. And these headphones work, firstly, without interacting with the hearing aid, and, secondly, they allow you not to remove the hearing aid, that is, they put on the headphones and the hearing aid and do not interfere with each other! ”
This is a Khabrovsk man, and we continue to communicate with him on this subject, but so far without any specific details.
Technical characteristics of Aftershokz:
* Please, if God forbid, you or your relatives have about the symptoms described, then before you buy headphones, or other devices described in this article, consult your doctor. Aftershokz is a headset, and are not a hearing aid, do not have a medical certificate.
** If you are in Moscow and are ready to come to the office, then you can test the headphones: we always have a sample!
*** If you buy Aftershokz as a headphone for sports, then do not forget about the code "Geek", which gives 7% percent of any purchase.
Take care of yourself!
Buy Aftershokz
I will begin with a picture in which our sound-conducting system is schematically depicted, and formally everything I need to know about it: I have three ears, an outer, middle and inner, and each of them is at risk. At the same time, according to statistics, neurosensory hearing loss, unfortunately, accounts for more than 70%, and therefore the problems of people with lesions of the external and middle ear for a long time were, as it were, on the 2nd plane.
Bone conduction apparatus
')
In most cases, when it comes to a hearing aid, a picture of an intra-ear or ear-ear device appears before your eyes, which converts an acoustic signal into an electrical one and vice versa, amplifying it. However, in some cases, the use of such a device is meaningless.
And if the sound-conducting system is impaired at the level of the external and middle ear, then physicians may recommend hearing aids with bone conduction. Of course, without consulting an audiologist and research on an audiometer, it is better not to test any devices on yourself! On a typical threshold audiogram, in this case there will be high thresholds for airborne sound and a normal perception of bone sounds, in contrast to neurosensory disorders. The Rinne test in the case of conductive hearing loss will be negative if the tuning fork is heard longer through the bone than “through the air”.
The technology of bone conduction of sound has been discovered long ago, Nobel Prizes have been obtained, and to understand that people with conductive hearing loss can live and work normally, you can remember Beethoven: he finished writing his quartets when he was seriously ill, and used wooden sticks between his teeth as a tool .
The book “Music and Medicine” by Dvoretsky clarifies that the disease that struck the composer was at first accompanied by the loss of high tones and the painful perception of loud sounds, but the bone conduction remained, so we now have the pleasure to listen to such music.
15th quartet of Beethoven, 1825. The composer is already seriously ill
The “dental method,” which the genius used, was later reviewed, described, and the outstanding scientist Bekesy later proved the regularity between the lower jaw and the bone conduction of sound, and nowadays such studies are carried out in the United States. In particular, the experiment described in the journal Special Care in Dentistry shows that among more than 1,000 patients, bone conduction was worse in people with fewer teeth. In total, 5, 3 percent took part in the experiment - they had no teeth; 15, 4 - had less than 17 teeth.
Diagnostics show that bone conduction devices can also be prescribed in such cases:
- Bilateral atresia of the external passage
- Bilateral chronic purulent otitis media
- Postoperative large open mastodial cavity
- Inflammatory processes in the external system
Bone devices convert sound into vibrations transmitted to the solid tissues of the skull, from where to the cochlea of ​​the inner ear.
In form, these hearing aids were different, and some sensors could even be located on the arms of the glasses, but all non-implantable devices could be accompanied by painful sensations due to the pressure that the headbands of such "gadgets" had.
Also, the disadvantage was:
- Vibrators did not have a broadband frequency response
- The position of the implantable sensor was not fixed, changed and the audibility deteriorated
- Pocket hearing aids were accompanied by additional noise caused by rubbing against clothes.
- Dimensions and appearance
Therefore, BAHA bone hearing aids have actually been a monopolist for a long time on the market, whose studies, in particular, in the journal Clinical Otolaryngology can be found since the mid-1990s.
They could be barely noticeable and almost did not give out health problems, but the process of “integration” of such a device was slow.
BAHA devices are multipart: processor, “adapter” and “pin”, which were implanted into the skull, which was possible due to the “livability” of bones and titanium, discovered by Professor Branemark.
- The sound processor transforms, processes and amplifies the acoustic oscillations.
- The intermediate part transformed acoustic vibrations into mechanical ones and transferred them further.
- The titanium pin transmitted these vibrations to the cochlea.
At the same time, the integration of such hearing aids took place in two stages: the implantation of a titanium pin and six months later (during this time it grew together with a bone) “hanging” the processor.
There were complications! Infections could occur, hard tissues could be damaged, surrounding tissues could inflame and a pocket could appear that made the implant moveable, and among the most frequent were inflammation of the skin around the pin.
However, neither this nor the tests in medical journals stopped people. By the way, repeatedly repeated experiments did not convincingly prove the “super-ability” of BAHA and non-universality. This conclusion was made in 1999 in the same “Clinical Otolaryngology”, later, in our days, researchers JL Colquitt, E. Loveman, DM Baguley and others, referring to previous experience, told about the advantages of such devices in some cases ". Already in 2015, the journal Laryngoscope clarifies that despite the colossal previous experience, research is not enough, and they must continue.
Thus, if you look 10 or 15 years ago, the comparative table of hearing aids with bone conduction sound could be like that.
Similar to the BAHA principle, the more modern Alpha digital hearing aids work, they are also implantable, but they provide ample opportunities in terms of noise suppression, etc.
It should be added that as early as 1990 doctor GG Browning believed that implanted hearing aids with bone sound transmission might not be relevant for every bone conduction threshold.
Today's research, which has become more targeted, "sighting", considers all possible variants of dependencies and cause-effect relationships that can provoke hearing impairment. At the same time, despite the fact that the inner ear of a person turns out to be “less protected”, since it is formed first of all, on the 4th week of pregnancy, intrauterine deafness is manifested only in 13% of cases, and immediately after birth - in 59% of cases.
Modern researchers, for example, Pascal Dollé and Raymond Romand, in 2006 on the pages of the Journal of Neurobiology, clarified that in many respects the precursor of hearing impairment is the lack of retinol (Vit A) in the body, however, of course, the morphogenesis of the inner ear is affected not only by the lack of the right amount of a particular vitamin.
Also, the role of mutations of the GJB2 gene, which encodes the transmembrane protein connexin 26, which participates in the intercellular contacts in the tissues of the inner ear, is noted, but the frequency of congenital neurosensory hearing loss associated with this gene is 1: 1000 in newborns.
Gjb2
A special role for hearing problems is assigned in geriatrics. In a number of publications it is argued that such an obvious cause of hearing impairment, such as aging, does not allow many to come to terms with it in old age. Dr. Allan Sinclair, in his work, argues that this causes a much more serious problem: the elderly are depressed, and there are frequent cases of attempted suicide!
The fact that the problem is massive and global, can say, for example, such a collective work of doctors Adriaan Moelker, Ronald AJJ Maas, Mohamed Ouhlous. Their research is devoted to the influence of MRI devices on the human sound system. The study was conducted in 2005, 10 years ago.
Google handles
Interest in bone conduction with glasses Google was excited by a journalist who complained that the glasses are unsuitable for people with disabilities. At the same time, it seems he didn’t have to rely on anything because his auditory system had lesions in the inner ear, and therefore there was little bone conductivity could be useful to him.
Nevertheless, Google demonstrated this technology again and showed that now in some cases, it’s not enough that you don’t have to drill the skull and wait for half a year to “implant” the titanium, but you don’t have to pay 200,000 rubles for it Our money for the devices BAHA! On the other hand, not everyone was comfortable wearing glasses, and not everyone needed to, but small and proud Aftershokz, who at that time seemed to lack his authority to shout out loud, came to life. And a year later there was a real flourishing and hundreds of press references.
However, despite the fact that even the Aftershokz logo transparently hints at the hearing impaired, they have built an advertising campaign on a different strategy.
Aftershock in the press
In the international and domestic press, “Aftershokz” is increasingly featured as headphones for sports, according to the headlines in Mashable, “Los Angeles Times”, in English “Independent”, “techlicious”, “Men'sHealth” and private reviews.
There are reasons for this, and Aftershokz today is called headphones, safe for athletes, especially for cyclists: headphones do not cover their ears, and therefore a person can hear ambient sounds, car signals, etc.
This is supported by international statistics on the number of accidents involving cycling. In particular:
United Kingdom - 2013
- 19,438 bicycle accidents
- Severe injuries received 2 867 adults
- lungs - more than 14 thousand adults
- During the year, 6 children and 103 adults died on the roads in an accident
In the United States in 2012 killed more than 700 cyclists.
Head injuries are among the most common fatal injuries.
During the same period, 271 road accidents involving a bicycle were shown in Moscow, in which 2 people died (1 child), 11 people were seriously injured (2 children).
In this sense, Aftershokz is an absolute breakthrough, because “shifting” the headphones above the ears and increasing the volume did not give such a perception, and plus to everything, there is a microphone in the headphones, so many simply use them as a means of communication.
Judging by the reviews, a certain vibration, which is logical for bone conduction devices, was haunted by many for some time, but got used to it very quickly. Or resigned.
My client
Unfortunately, today I have only a theoretical understanding that in some cases with hearing impairment, Aftershokz’s capabilities will be useful. The only clue now is the client's feedback, who took the headphones from us for his grandfathers.
I quote literally:
“With headphones everything is fine - the first tests went off with a bang. Without any additional devices, grandfathers without hearing aids can communicate tolerably by telephone, which is quite surprising for them. That is, we connect the headphones as a headset to the phone and everything - the grandfathers can talk on the phone and hear quite well. ”
And in the second letter:
“The most curious thing is that one of my grandfathers is almost completely deaf, hears only one ear, and even that is only 5-10% compared with a healthy person. But even he heard enough when we talked with him on the phone, which means that he can already walk with a mobile phone and answer if something happens, and in addition, at the same time he can wear his hearing aid.
The other grandfather hears much better, although much weaker than a healthy person. On the phone with him, however, I could not talk - he could not hear what I was saying to him, and yesterday I directly felt that he was hearing me well, almost like an ordinary person.
Ordinary headphones, worn on a hearing aid, did not give such hearing to any of my grandfathers. And these headphones work, firstly, without interacting with the hearing aid, and, secondly, they allow you not to remove the hearing aid, that is, they put on the headphones and the hearing aid and do not interfere with each other! ”
This is a Khabrovsk man, and we continue to communicate with him on this subject, but so far without any specific details.
Technical characteristics of Aftershokz:
- Speaker type: bone conduction transducers
- Frequency range: 20 Hz - 20 kHz
- Speaker Sensitivity: 100 ± 3 dB
- Microphone sensitivity: -40 ± 3 dB
- Bluetooth Version: 2.1 + EDR
- Compatible Profiles: A2DP, AVRCP, HSP, HFP
- Communication range: 10 m
- Battery Type: Lithium Ion
- Work time: 6 hours
- Standby time: 10 days
- Charging time: 2 hours
- Black colour
- Weight: 41 grams
* Please, if God forbid, you or your relatives have about the symptoms described, then before you buy headphones, or other devices described in this article, consult your doctor. Aftershokz is a headset, and are not a hearing aid, do not have a medical certificate.
** If you are in Moscow and are ready to come to the office, then you can test the headphones: we always have a sample!
*** If you buy Aftershokz as a headphone for sports, then do not forget about the code "Geek", which gives 7% percent of any purchase.
Take care of yourself!
Buy Aftershokz
Source: https://habr.com/ru/post/366907/
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