LordNikon

Indeed! I need a testing monkey...

Oh, I am certainly not giving up on this. I am just prioritizing the construction of my armor first. :-) The app basically works as it is now. The most important thing that certainly could be better is getting the voice manipulation just right...

I am currently building my armor so that I can actually test the app :-) Making the sound more "tinny" is indeed top priority for the app. I am also considering making it able to play pre-recorded samples... But first: Figuring out how all these white armor pieces fit together in a way that is not impossibly uncomfortable ;-)

It seems you have used the app more in practice than I. Do you have any input on the voice manipulation or noise effects? In what way do you think it can be improved?

There could be battery damage issues if the batteries are not completely even. Depending on the battery chemistry. But why not use a 5V fan? They are less common, but do exist. A USB fan perhaps? :-)

So, do you like the new hands-free function of the app? :D The app itself is just a user interface. It starts a background service to do the actual audio processing. You can close the app, or turn the screen off. The audio processing background service remains active until you press the trashcan button in the app. My guess is that perhaps you unintentionally left the background service running long before you hooked it up to your car? I should probably add a system bar indication that the background service is active, similar to what spotify does...

I had great success using acoustic echo cancellation to battle feedback in my Android voice amp app experiments. Should work equally well for hearing improvements... Perhaps there should not be one, but TWO Android phones in the bucket. One for voice amp, and one for hearing improvements. I could do both voice amp and hearing improvements in one app, but I would be one audio channel short. Mono hearing improvements? Nah... Hmmm... Well, we are looking for two 'droids, are we not?!?

It looks like the updated version with Acoustic Echo Canceling is up on google play now. Let me know if it works better for you.

Feedback is a big problem. And there is little I can do about it in software. It is all about preventing the speaker output from reaching the microphone. What kind of speaker do you use, and where do you place it? EDIT I may have been mistaken... Android has an Acoustic Echo Canceler for when using the speaker phone function. I tried enabling this, and it seems to make a pretty big difference when it comes to reducing feedback. Unfortunately, it does not seem to be available in Android versions older than 3.0, so I had to drop support for older devices for now. Let me know if it solves your feedback problem.

Just uploaded a new version which should be able to keep running even with the screen off. You will probably see the new version within a couple of hours. Press the microphone button to start the background service, and the trashcan to stop it. Ripper_L: Weird... I'll see if I can find out why. Unfortunately I don't have a bluetooth headset. elleerre: I'am an Android Jedi. But you are welcome to make an app for the sith-lords. If we enable bluetooth on both the iOS and the Android version, then the Android app can automatically play the phrase "I feel a disturbance in the force", whenever an iOS device with the app running gets close. :D

As I said, barely "proof of concept" state. :-) Being capable of running with the screen off is certainly needed. Have not done that before, but I'll figure it out. Think I need to register a background service in the Android system for this. I also consider adding a effect which makes the voice sound a bit more robotic/metallic in addition to the pure bandpass filtering.

The idea is to hook up a speaker to the phone, and put a microphone in your helmet. (Or stick the entire phone in the helmet and use the integrated microphone) The result should be amplification/modification of your voice and some added sound effects, so that you sound a bit like troopers in the movie. A icomm and ROM/FX clone, basically. Maybe when it is a bit more finished. Hook up a speaker or a headset to your phone and try it out if you want to find out what "white noise within the frequency range 400-5000Hz" sounds like :-) (It sounds like walkie-talkie static) At the moment I focus on "output" only. In the long run I'd like to add extra features, such as "input" from the outside world, extra sound effects, communication with other troopers, and possibly some kind of integration with helmet fans and such. Some phones should actually be able to power the fans. With really advanced optics, perhaps the display of the phone could be projected onto the lenses in the helmet for an in-helmet display? Would be kind of cool. But I doubt it would be feasible.

I think I have a better noise burst after playback now. It is white noise within the frequency range 400-5000Hz. I have played around with more filter settings. I changed the voice effect to 1000-5000Hz which seems to be a bit closer to the ROM/FX, but it is really hard to to determine if my voice-effect is similar to the ROM/FX or not from only listening to a video, since the voice of the person in the video is very different from my own to begin with. It might be that in additon to (or instead of) bandpass filtering, the ROM/FX makes the voice a bit "metallic" as well. Not sure. I am actually not entirely convinced that the ROM/FX effect is particularly authentic to the movies. I think I'll need to find more samples of authentic stormtrooper chatter to analyze. Guess I have to watch star wars again.

By "static breaks" do you mean the noise burst at the end of each playback? I already have a white noise burst in place for that purpose. But it could sound better. Perhaps I'll replace it with some sampled static. I tried tightening the bandpass filter to cut out everything but 1500-3000Hz. This changes the voice in a more dramatic way. Updated verion on it's way up to play.google.com I have made a small discovery: Some headphones with built in microphone has crosstalk between the microphone and headphone wires, causing echo. Regular headphones without microphone solves this problem.

Just uploaded a new version where the Voice activation works pretty well. (May take a couple of hours to show up on play.google.com) What further voice manipulation should be done to get a better "trooper effect"? Right now I am doing bandpass filtering to 300-3000Hz, and add some background noise. But it is not quite right, is it?

The microphone and speaker on phones and tablets are simply located too close together. The app has to be used with external microphone, speaker or headphones, otherwise you will get the feedback loop.

Just uploaded a version with a less nasty noise effect after playback. It also has some added background white noise. Should become available at play.google.com in a couple of hours.

No, no fancy things like muting other sounds at the moment. As I said, it is barely in "proof of concept" state. :-) Which is most important? Reliable voice activation, or a convenient push-to-talk function? There are bluetooth "buttons" which could possibly be used for push-to-talk... Such as this: http://flic.io/

I had a sudden burst of inspiration and decided to try out the concept of a Smartphone app for helmet audio. I have only spent 5 hours or so on this, so it is only in a "proof of concept" state, if even that. It is voice activated, performs bandpass filtering (300-3000Hz) on your voice, and plays it on the audio output. It ends the playback with a noise burst. The voice activation is currently crap, and there are no adjustments possible at all. The audio processing code is wildly inefficient. It may not work well on slower phones. And the Application icon is made in MSPaint. In short: Do not expect any kind of greatness at the moment :-) I uploaded it to the google play store in its current state, if someone wants to play around with it. It is called "Troop Talk Beta" ---------- Warning: Do NOT start the app on your phone without connecting a headset first, or you will get some nasty feedback.

Reviving this old thread a bit... I think using a generic platform such as a smartphone could have advantages, if just a working setup can be devised. A smartphone app could easily do all these things: * Voice amp, voice manipulation, and noise. * Amplify ambient sounds and play back in headphones. * Play prerecorded sounds. "These ARE the droids we are looking for!" "Imperial theme", ... * Sound effects for the weapon. * Intercom with other troopers. * And so on... If all troopers have the app, then the imperial theme could be played synchronized by all troopers while marching. The big question is: Is it possible to hook up sufficiently many audio inputs and outputs? * Three microphone inputs. (One for voice amp, two for recording ambient sounds in stereo) * Three, or possibly four, speaker outputs. (One for voice amp, stereo headphones, and optionally a separate speaker for weapon effects) USB is one way to add more inputs and outputs to a phone. Bluetooth another. Android has decent support for selecting video from multiple camera sources. Perhaps it has similar support for multiple audio devices? Regarding controlling a phone while in armor. How about those Android bracelets/watches? Just make sure the gloves are conductive enough to use a touchscreen. There is probably a spray for that...