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mark61
07-31-2008, 05:54 PM
Does anyone know what hertz range electric motors produce noise in? New hearing devices are programable enough that I think we may be able to remove most of the all encompassing over bearing electric motor noise related to machining. I know it is not going to be 1 single rating. The general range would be a good place to start.

mark61

Just Bob Again
07-31-2008, 06:35 PM
Got a job ahead of you. The motor itself will make noise at multiples and submultiples of 60 Hz. A 2-pole at 30 Hz and harmonics. 4-pole at 15 and harmonics. That's for an induction motor. Series or shunt, like vacuum cleaners can be anything. That's not counting the mechanical arrangement. The motor itself is usually pretty quiet if it's working right. Gear it down or use belts and you get noise from the power train. That depends on the gear ratio, etc. Bearings make noise, too. Cheap ones, anyway. So do sympathetic vibrations from the case and cutting noises.

I'm not sure a hearing aid is "smart" enough to distinguish. A person can pretty easily identify the sound. "that sounds like some kinda motor". I don't know you can make a hearing aid smart enough to blot out the harmonic structure of a motor versus something else with a complex structure that you do want to hear, like a violin.

Evan
07-31-2008, 07:39 PM
It depends on what you are trying to accomplish. You can buy active noise canceling headphones that will reduce external noise regardless of what type it is and let you listen to music without the interference. They work by sampling the outside noise, inverting the phase and then reproducing the phase inverted signal at your ear at the same volume as the noise. That results in near total cancellation of the noise. If the hearing aid can do that then it will work pretty well. The noise canceling technology was originally developed for hearing aids so make sure you buy the right type.

Bob Ford
07-31-2008, 11:42 PM
Mark61

I have been using hearing aids since the 80s. I do not have noise problems from motors or florescent lighting, except when I use the T position in order to hear on the telephone. If I am near florescent lights they make a terrible noise in the aids. Have not tried the telephone position near motors. In normal use they are fine around motors or lights. For those that do not know in the T position normal sound is turned off and the inductance in the phones ear piece is picked up by a coil in the hearing aid. For us that can not hear it eliminates all the back round noise and we hear only the sound on the phone. Unless you are near radio stations high, power lines, or most anything that is putting out a signal.

Bob

mark61
08-01-2008, 07:14 AM
Thanks for the replys so far. I know the sounds are going to be varied. It has been 32 years since I heard but I do remeber how unique things can be. The "T" setting Bob refers to is called the telecoil induction loop. It was a major set forwards in hearing aid designs. As for my self, I have cochlear implants. Electrodes inmplanted in the cochlea that stimulate the nerve with electrical charges. The new proccesser's are truely amazing and do have noise canceling features. Also the programing can be set very precicly in steps as small as (I think!) 5 hertz ranges. Every time I get a new proccesser it takes several to a half dozen programing tweaking to get the most out of it. The more educated I can be about the sounds I like and do not like the easier it is for the audiologist to program them. It is truely amazing how small but powerfull the proccesers are now!
Thanks,

mark61