My intentions have always been genuine, not just "originally".
That said, the point you raise about naivety impairing development is a good one. As a young graduate fresh out of university, I had no idea how hard it is to get from an idea to a product. Now I'm wondering how often such things happen, too...
OK, so you're not using DAI (Direct Audio Input) stuff at the moment. It might be a good plan to ask your audiologist about using DAI with your aids first, then. If you get a positive answer, try plugging the DAI into a CD player or somesuch as a proof of concept. Hopefully, that will give you more of an idea whether a Bluetooth module is practical for you.
I usually just put the phone on a table and wander about the room. Theoretical maximum range is ten metres, although I'm not usually beyond five. I've also discovered that having the phone in my backpack works, provided that all the wires are kept in front of me. Human flesh obviously absorbs microwave RFI...:-) although the Bluetooth link coped, somehow. Interesting.
That last paragraph is an excellent thought. I'd lean towards variable amounts, though, decided by voting among the site users/members. One pound from your donation goes to each person you cast a vote for, perhaps?
Oops - I should have said that the closer such an idea got to actual patents and real production, the larger the bonuses were. I probably shouldn't give any more detail, but Ericsson certainly weren't penny-pinching.
Mind you, I am curious to know what their current policy is - any Ericsson people about who can comment?
Yes; I deliberately wanted to spread the information so that as many people as possible would know. Slashdot is a key site for that, incidentally. I'm hoping that people will start thinking about the basic idea and making the devices commercially. Someone might even come up with related ideas or extensions I didn't think of, which could be a big win for me and deaf people like me.
That's a 2-year old T68, by the way, I don't think you can get that style anymore. I'm not even sure if the faceplate can be changed, actually. Try EBay?
Sorry, I missed the image link the first time round... Some of those aids look like they would accept DAI shoe connections - if so, then my style of Bluetooth conversion should work, in theory. Unfortunately, the only way to find out is to try, and a serious mistake could fry your hearing aid. That's why I wouldn't make one for someone else, because I don't want to assume that kind of risk.
I've never seen a bone-conduction aid, although I've heard about them. I'd need a lot more information before I could say much that was useful, though. For example, when you use a fixed-line phone, a portable CD player, or an FM lecture theater microphone, how do you get the audio into your aid?
The root cause is definitely the RF transmission, or a system directly related to it, although I don't have the entire lab's worth of resources I'd need to determine the exact mechanism.
There's no interference if the phone is quietly switched on and not sending to the network, even if you're playing games or something on it. It only appears during radio transmission, either during a voice call or during the few seconds it takes for an SMS to transfer. I generally know an SMS is coming in before the phone does - the sound is quite distinctive.
The web page I wrote was intended for an intelligent layperson, so I deliberately omitted abstruse discussions of the various RFI-related mechanisms that might be at work.
You're probably right about the GHz frequencies as such, but the bursty nature of the transmission is another thing entirely. I suspect that it embodies the audible frequencies I hear as interference in what one might call unintended modulation.
A hi-fi enthusiast once told me that he can hear SMS arriving on the hi-fi downstairs with the phone upstairs, almost certainly for the same reason. This Motorola link has sound samples, for anyone who wants to know what these things sound like.
I considered optocoupling, but I liked the idea of wirelessness - having wired stuff attached to your hearing aids can be a problem. If you drop the device your headphones are plugged into, you'll probably get away with it, even if the device doesn't. Either the headphones unplug, or fall off, or the jerk is distributed enough not to hurt.
Do that with a hard connection to a hearing aid, and trust me, it'll hurt, because the hearing aid is set right into your ear. (The innermost end isn't more than a few millimetres from your eardrum.) I'm speaking from personal experience, unfortunately...
The previous poster also raises good points with respect to optocoupling.
On a sidenote, hearing aid wearers learn to protect their ears very early on - it's an extra place to take a hit in sport, or a dirty blow in a fight.
I tried filtering at both ends, in various forms and combinations. LostCluster is right.
Mind you, the extra weight of an RFI filter hanging off the hearing aid would be something to avoid, even if it did work. Since it has to be as close as possible, you can't just park it on your shoulder, or somesuch.
Your last thought goes further than the commentary on my web page, though - it suggests an appeal to at least part of the normal-hearing market, which might just tip the balance for a manufacturer.
Uh huh. I wrote that page with no frames, no divs, no tables, in short, no fancy-format crap. To the best of my knowledge, it should be fine with a screen reader or Braille line - even the images at least have a little ALT text.
Why? Some causes of deafness take your eyesight down too...
The Bluetooth headset radiates about 1mW at radio frequencies - even if the entire milliwatt were converted to heating your ear with 100% efficiency, you wouldn't feel it. Naturally, most of the RF radiates into space, otherwise Bluetooth wouldn't work. What you can feel is the heat generated by the headset circuitry - the audio transducer alone will account for tens of milliwatts.
Also, a mobile handset in an area with excellent signal strength will radiate about 50mW of RF, rising to about 500mW in areas with a poor signal. If I remember correctly, some of the first generation analogue cellphones could radiate a full watt. All of these are much stronger than Bluetooth.
The problem is very dependent upon the combination of hearing aid and telephone models. My hearing aids unfortunately seem to be at the sensitive end of the spectrum, hence my need for the Bluetooth solution. If you have something that works for you, stick with it!
Should you ever have to change, make absolutely certain that you comprehensively test your planned new setup before you part with any money. One good thing to try whilst testing is to find a location with poor mobile signal strength, so that the phone has to transmit at full power, giving you the highest chance of detecting any RFI problems.
You know, the thought had never even crossed my mind... thank you for that, it made me laugh!
As mboverload says, I wrote the disclaimer in capitals because everyone seems to do it that way. I'm not sure why, although I suspect it might be so that people can't claim that a disclaimer was "hidden in the surrounding text" or somesuch. If someone could claim that the disclaimer was hidden so they wouldn't notice it, they might just be able to sidestep it on the basis that it hadn't been made clear, and demand damages anyway.
The reason my page doesn't have a clickable contents list with in-page link targets is so that people are forced to start at the top where the disclaimer will be presented to them up front. Mind you, I can't help feeling that it's a shame we live in a day and age where this kind of legal paranoia is necessary...
Slashdot Mirror
My intentions have always been genuine, not just "originally".
That said, the point you raise about naivety impairing development is a good one. As a young graduate fresh out of university, I had no idea how hard it is to get from an idea to a product. Now I'm wondering how often such things happen, too...
OK, so you're not using DAI (Direct Audio Input) stuff at the moment. It might be a good plan to ask your audiologist about using DAI with your aids first, then. If you get a positive answer, try plugging the DAI into a CD player or somesuch as a proof of concept. Hopefully, that will give you more of an idea whether a Bluetooth module is practical for you.
My immediate thoughts:
:-)
- I'm not surprised it took a deaf engineer to do it.
- Damn, I should have gone to work for Nokia, not Ericsson.
These devices don't work for me, unfortunately, or I'd've had one years ago
I beg to differ.
I usually just put the phone on a table and wander about the room. Theoretical maximum range is ten metres, although I'm not usually beyond five. I've also discovered that having the phone in my backpack works, provided that all the wires are kept in front of me. Human flesh obviously absorbs microwave RFI... :-) although the Bluetooth link coped, somehow. Interesting.
Paragraph 1 - thank you.
Paragraph 2 - it's not.
Paragraph 3 - that was a part of my decision to write it up for Ericsson. No sell-out, though.
Unfortunately, I can't properly defend my assertions without disclosing things I'm not allowed to. Sorry.
That last paragraph is an excellent thought. I'd lean towards variable amounts, though, decided by voting among the site users/members. One pound from your donation goes to each person you cast a vote for, perhaps?
Thank you; naturally, my thoughts on the usefulness of my ideas differ from yours :-)
Oops - I should have said that the closer such an idea got to actual patents and real production, the larger the bonuses were. I probably shouldn't give any more detail, but Ericsson certainly weren't penny-pinching.
Mind you, I am curious to know what their current policy is - any Ericsson people about who can comment?
Yes; I deliberately wanted to spread the information so that as many people as possible would know. Slashdot is a key site for that, incidentally. I'm hoping that people will start thinking about the basic idea and making the devices commercially. Someone might even come up with related ideas or extensions I didn't think of, which could be a big win for me and deaf people like me.
That's a 2-year old T68, by the way, I don't think you can get that style anymore. I'm not even sure if the faceplate can be changed, actually. Try EBay?
Sorry, I missed the image link the first time round... Some of those aids look like they would accept DAI shoe connections - if so, then my style of Bluetooth conversion should work, in theory. Unfortunately, the only way to find out is to try, and a serious mistake could fry your hearing aid. That's why I wouldn't make one for someone else, because I don't want to assume that kind of risk.
I've never seen a bone-conduction aid, although I've heard about them. I'd need a lot more information before I could say much that was useful, though. For example, when you use a fixed-line phone, a portable CD player, or an FM lecture theater microphone, how do you get the audio into your aid?
That is exactly what my hearing aids do when an SMS arrives.
The root cause is definitely the RF transmission, or a system directly related to it, although I don't have the entire lab's worth of resources I'd need to determine the exact mechanism.
There's no interference if the phone is quietly switched on and not sending to the network, even if you're playing games or something on it. It only appears during radio transmission, either during a voice call or during the few seconds it takes for an SMS to transfer. I generally know an SMS is coming in before the phone does - the sound is quite distinctive.
The web page I wrote was intended for an intelligent layperson, so I deliberately omitted abstruse discussions of the various RFI-related mechanisms that might be at work.
You're probably right about the GHz frequencies as such, but the bursty nature of the transmission is another thing entirely. I suspect that it embodies the audible frequencies I hear as interference in what one might call unintended modulation.
A hi-fi enthusiast once told me that he can hear SMS arriving on the hi-fi downstairs with the phone upstairs, almost certainly for the same reason. This Motorola link has sound samples, for anyone who wants to know what these things sound like.
I considered optocoupling, but I liked the idea of wirelessness - having wired stuff attached to your hearing aids can be a problem. If you drop the device your headphones are plugged into, you'll probably get away with it, even if the device doesn't. Either the headphones unplug, or fall off, or the jerk is distributed enough not to hurt.
Do that with a hard connection to a hearing aid, and trust me, it'll hurt, because the hearing aid is set right into your ear. (The innermost end isn't more than a few millimetres from your eardrum.) I'm speaking from personal experience, unfortunately...
The previous poster also raises good points with respect to optocoupling.
On a sidenote, hearing aid wearers learn to protect their ears very early on - it's an extra place to take a hit in sport, or a dirty blow in a fight.
I tried filtering at both ends, in various forms and combinations. LostCluster is right.
Mind you, the extra weight of an RFI filter hanging off the hearing aid would be something to avoid, even if it did work. Since it has to be as close as possible, you can't just park it on your shoulder, or somesuch.
Precisely.
Your last thought goes further than the commentary on my web page, though - it suggests an appeal to at least part of the normal-hearing market, which might just tip the balance for a manufacturer.
Interesting!
Uh huh. I wrote that page with no frames, no divs, no tables, in short, no fancy-format crap. To the best of my knowledge, it should be fine with a screen reader or Braille line - even the images at least have a little ALT text.
Why? Some causes of deafness take your eyesight down too...
The Bluetooth headset radiates about 1mW at radio frequencies - even if the entire milliwatt were converted to heating your ear with 100% efficiency, you wouldn't feel it. Naturally, most of the RF radiates into space, otherwise Bluetooth wouldn't work. What you can feel is the heat generated by the headset circuitry - the audio transducer alone will account for tens of milliwatts.
Also, a mobile handset in an area with excellent signal strength will radiate about 50mW of RF, rising to about 500mW in areas with a poor signal. If I remember correctly, some of the first generation analogue cellphones could radiate a full watt. All of these are much stronger than Bluetooth.
The problem is very dependent upon the combination of hearing aid and telephone models. My hearing aids unfortunately seem to be at the sensitive end of the spectrum, hence my need for the Bluetooth solution. If you have something that works for you, stick with it!
Should you ever have to change, make absolutely certain that you comprehensively test your planned new setup before you part with any money. One good thing to try whilst testing is to find a location with poor mobile signal strength, so that the phone has to transmit at full power, giving you the highest chance of detecting any RFI problems.
You know, the thought had never even crossed my mind... thank you for that, it made me laugh!
As mboverload says, I wrote the disclaimer in capitals because everyone seems to do it that way. I'm not sure why, although I suspect it might be so that people can't claim that a disclaimer was "hidden in the surrounding text" or somesuch. If someone could claim that the disclaimer was hidden so they wouldn't notice it, they might just be able to sidestep it on the basis that it hadn't been made clear, and demand damages anyway.
The reason my page doesn't have a clickable contents list with in-page link targets is so that people are forced to start at the top where the disclaimer will be presented to them up front. Mind you, I can't help feeling that it's a shame we live in a day and age where this kind of legal paranoia is necessary...