Microphone in to headphone out

Hello, Im in need of some major hand-holding. I have no experience with arduino, any other similar solutions, or electric engineering in general, but I dont know of any other options for what I need that would suffice. I do have a background in tech, mainly software, and majored in comp sci, so I believe keeping up will be possible for me.

Im trying to make a portable hearing assistance device for an elderly relative that refuses to wear a hearing aid for reasons that Id rather not get into. The existing stuff thats out there is either crap in terms of quality or quite pricey.

The device, as I see it, should consist of a 3.5mm mic input (preamp), 3.5mm headphone output, volume control (amp), a battery pack (preferably rechargeable), and an on/off switch. Due to the purpose of the device, the sound feed needs to be passed through in as close to real time as possible with minimal processing other than volume.

Found this mic preamp:https://www.sparkfun.com/products/8872 and this VU shield: http://macetech.com/store/index.php?main_page=product_info&products_id=11 but thats from some high level searching and I dont know what else to look for.

What type of hardware would I need for this? Are there any software requirements? Is there anything Im missing or havent considered? Has anybody done anything similar and willing provide guidance?

I have no idea where to start and would really appreciate some help.

What you want is called an "amplifier".

Thank you for the detailed reply, but Im not sure what you mean. My understanding is that plugging a mic into the input of an amp or “amplifier” and a headset into the output wouldnt work as the mic requires a preamp. It is quite possible that I may be mistaken here and would appreciate any clarification.

Not all mics require a pre-amp. There is absolutely no need for an arduino in this device at all. Mic-Amp-Headphones. That is all that is required.

There are thousands of different amplifier designs to choose from. Some easy, some hard. Hell, you could even buy one with little trouble and not have to actually make anything.

Solved problem: http://www.amazon.com/Bionicear-G2-Personal-Sound-Amplifier/dp/B005D8NNLM/ref=sr_1_2?ie=UTF8&qid=1343890950&sr=8-2&keywords=sound+amplifier

…And many other available, though this one seems least sucky.

Thank you, both, for your replies. I will go ahead and try one of the existing solutions.

grins: Thank you for the detailed reply, but Im not sure what you mean. My understanding is that plugging a mic into the input of an amp or "amplifier" and a headset into the output wouldnt work as the mic requires a preamp. It is quite possible that I may be mistaken here and would appreciate any clarification.

Let me clarify: you need an amplifier with a microphone input. Some only take a 'line in' input but there are plenty that will take a microphone input. Since you're only expecting to drive headphones you only need a very low power amplifier. I wouldn't expect any problem finding a low cost commercial amplifier to do the job, and it would be a relatively simple electronic project to make your own if you preferred the DIY route. Either way I'd be looking for an analogue solution, no need for a digital microcontroller here.