class D driving a hearing aid speaker !!

terminator12 · 15th July 2010, 02:56 PM

hi friends,

Am doing an integrated-circuit design for driving high impedance load like that of a speaker inside a hearing-aid. I am adopting a closed-loop PWM class-D which is of non-self oscillating type. I am currently facing some issues which I am unable to solve myself.

The first is that am finding it difficult to find the appropriate speaker models for that used within a hearing aid. I tried a lot of googling but I am not able to get any. Any help would be greatly appreciated.

thanks in advance,

Cheegii · 15th December 2010, 08:50 AM

Me too

gooki · 15th December 2010, 09:10 PM

Just buy a complete unit and strip for parts:
DealExtreme: Search for hearing aid (101 products in 30 categories)

Andrew Eckhardt · 15th December 2010, 09:18 PM

The issue of power consumption and distortion in hearing aids is so serious it might only be competitive to design the amplifier for a particular driver design. I imagine the variation in load impedance of commercially available product could be as wild as seen in headphones, except for maybe a more limited supply voltage range.

phase_accurate · 16th December 2010, 06:35 AM

Just curious: Why are you given the task to develop a class-d amp for a hearing aid and at the same time you will not be provided with the properties of the transducer involved ? Or are you developing a solution that should cover a wide range of transducers ?

Regards

Charles

Cheegii · 17th December 2010, 01:49 AM

First Hearing aid is expensive in our country? Second, analog hearing aid's battery no long lasting and self oscillating. Beep! I would try to build another design like small mp3 player.

Trocadero · 17th December 2010, 02:22 AM

Try in-ear receivers from:
Star Micronics (used in e.g., Etymotic earphones)
Subminiature Speakers :: Knowles
Sonion
Regards,
Erik Ostlin

15th July 2010, 02:56 PM	#1
terminator12 diyAudio Member Join Date: Apr 2010	class D driving a hearing aid speaker !! hi friends, Am doing an integrated-circuit design for driving high impedance load like that of a speaker inside a hearing-aid. I am adopting a closed-loop PWM class-D which is of non-self oscillating type. I am currently facing some issues which I am unable to solve myself. The first is that am finding it difficult to find the appropriate speaker models for that used within a hearing aid. I tried a lot of googling but I am not able to get any. Any help would be greatly appreciated. thanks in advance,

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15th December 2010, 08:50 AM	#2
Cheegii diyAudio Member Join Date: Dec 2010	Me too

15th December 2010, 09:10 PM	#3
gooki diyAudio Member Join Date: Dec 2008	Just buy a complete unit and strip for parts: DealExtreme: Search for hearing aid (101 products in 30 categories)

15th December 2010, 09:18 PM	#4
Andrew Eckhardt diyAudio Member Join Date: Nov 2005 Location: PA	The issue of power consumption and distortion in hearing aids is so serious it might only be competitive to design the amplifier for a particular driver design. I imagine the variation in load impedance of commercially available product could be as wild as seen in headphones, except for maybe a more limited supply voltage range.

16th December 2010, 06:35 AM	#5
phase_accurate diyAudio Member Join Date: May 2002 Location: Switzerland	Just curious: Why are you given the task to develop a class-d amp for a hearing aid and at the same time you will not be provided with the properties of the transducer involved ? Or are you developing a solution that should cover a wide range of transducers ? Regards Charles

17th December 2010, 01:49 AM	#6
Cheegii diyAudio Member Join Date: Dec 2010	First Hearing aid is expensive in our country? Second, analog hearing aid's battery no long lasting and self oscillating. Beep! I would try to build another design like small mp3 player.

17th December 2010, 02:22 AM	#7
Trocadero diyAudio Member Join Date: Jul 2005 Location: Perth	Try in-ear receivers from: Star Micronics (used in e.g., Etymotic earphones) Subminiature Speakers :: Knowles Sonion Regards, Erik Ostlin

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