Extremely directional microphone

[jpoopdog]

I am going to install a raspberry pi in my car soon, and one of the things it will do is serve as my radio.
Long story short i need a microphone to accept voice controls to scan through the radio channels, my present radio cannot auto scroll until it reaches a station, and while i drive should i desire to look through channels, or to go through my preset channels, would leave me dangerously distracted, so the solution would be to use four different voice controlls to either auto tune up or down, or go up or down through my preset channels.

Problem is my car is quite noisy as you would imagine, plus theres noice from the radio itself. the solution fortunately is quite simple. An extremely directional microphone which can block any noise other than what is spoken directly into it. i plan on mounting it on the non moving part of the steering wheel so i can speak loudly directly into it, (i dont care if its loud, so long as its clear).

so i ask, does anyone know where i may source some super directional microphones as which i want, prefferebly as a base component and not built into some studio quality mic that will cost me a considerable amount?

thankyou

 

[MikeMl]

The only way I can think of making a highly directional mic is either the "shotgun mic" or using a parabolic reflector. Both of these are large, way too large to mount inside the car, let alone on the steering wheel. The laws of physics apply here: the thing that makes the mic directional has to have an "aperture" of several wavelenghs. Have you ever seen an organ pipe for the low notes?

You also need to think about something else. If you do mount something on the steering wheel, and have a crash, that object will now reside in your eye socket...

Get a old aviation headset with boom-mounted noise-cancelling mic. I use these in both my aircraft (which has a cockpit noise level probably 40db more than your car), and they improve the signal-to--noise ratio between the voice over the background noise by >10db.

For example, I have recorded cockpit voice conversations using a tape recorder. If I take the audio from the aircraft intercom (using the aviation headset mics), through a patch cable, the audio is understandable with only a slight amount of cockpit background noise. When I tried to use the built-in or even a lapel mic, the background noise was louder than the voices...

 

[jpoopdog]

i plan on placing it behind the wheel, so unless my head goes through the wheel, ill be safe, i cant place it on the wheen because that would require allot of messy wiring so that it could handle being turned around twice.
Ill try out your idea also if it doesnt work, i do hope it doesnt come to having to use a headset, but if it must be done then so be it.

 

[dougy83]

You could try cancelling the noise using active noise reduction, with one or more microphones. The background noise is learned (one way is to use an adaptive filter on the rPi) then subtracted from the speech + noise signal.

 

[dr pepper]

They make noise cancelling mikes for laptops, and come with a stand, you'd need to do a bit of hacking as they come with a usb interface, but you'd have a good platform starting with one of these.
You might even be able to connect it to the usb on your 'phone if it has one.

 

[electroyas]

how about an AI computer which can be trained to your voice and not for the noise, it could even learn to eleminate noise it self and perfect it self. Just an idea . I hope it could be done with raspberry pi and ai developing sofftwares