looking for an iPhone "microphone amp" application

November 24, 2008 8:11 AM

Is there an iPhone app (jailbroken or legit) that simply outputs the sound from the microphone directly to the headphones with no delay, as if it were an amp? I tried searching google and the iPhone store with no success.
posted by helios to technology (11 comments total)

Given that the headphone jack is meant only to power headphones rather than unpowered speakers, I don't think you'll get very much amplification.

Without knowing more, my guess would be that Apple would reject an AppStore version of such a program as being of limited utility. What purpose are you putting this to?
posted by jedicus at 9:26 AM on November 24, 2008

Sorry, by "amp" I just meant that it will pass through the microphone input to the headphones (which is just the normal amplification).

I want to be able to hear my own voice in the headphones in real-time so that I can practice pronunciation (French).

I could use a recorder app to record and play back, but that's too slow. I need instant feedback.

I am using a mixer to do it at home, but that's bulky and non-portable. And I want an iPhone app because I know it's technically possible (it happens when you make phone calls for example) and I don't want to carry around another piece of equipment for no reason.

And it's true that Apple might have reservations about approving such an app, but 1) I don't mind jailbreaking my phone for a non-approved app, and 2) I can find hundreds of apps in the App Store that are more worthless and do less than this one would do.
posted by helios at 9:40 AM on November 24, 2008

Okay, it's overkill, but FourTrack should be able to do this.
posted by jedicus at 9:57 AM on November 24, 2008

Nope, it doesn't. I guess the iPhone app platform doesn't support latency low enough for professional monitoring, but I'm still convinced that an app could do simple voice monitoring; a small (less than 100ms) delay wouldn't be an issue for my usage.

Thanks for your help so far, though.
posted by helios at 10:10 AM on November 24, 2008

Ah, my apologies. The FAQ made it sound like there was a direct pass through from the mic to the headphones. I'm glad you found the catch in the forums before dropping $10 on the app, though.

Smule's Sonic Vox claims to do real time voice alteration (think Darth Vader). Looking at the video, it seems like the latency is pretty low. I can't tell if it has a default 'no change' mode. If it doesn't, you might try contacting Smule and asking for a pass through mode in the next version. It should be trivial for them to add.
posted by jedicus at 10:37 AM on November 24, 2008

I did this exact thing last year with birthday messages from my kids' great-grandmother in Germany, after more than a year of saving them every week on the phone.
I did it via the land line, though. You don't mention if you're on a Mac, but I used the trial version of Ambrosia's WireTap (there's also this one and many others if you search for "phone" "record" etc.)
You just plug a phone cable from your computer modem into the wall jack, hit record and dial in to your messages. You can dial with another phone on the line or use a phone dialing app. Sounds convoluted but it worked pretty well.
posted by chococat at 11:40 AM on November 24, 2008

jedicus: I have tried Sonic Vox, but it doesn't have a normal mode (you can get somewhat close to normal, but you still sound a bit robotic), and the delay is much greater than the video (probably due to all the DSP). Maybe I'll mail them though.

chococat: Actually, I am not interested at all in recording phone conversations, I simply want to use my phone as a portable mic amplifier so that I can talk into it and hear my own voice in my headphones.
posted by helios at 2:49 PM on November 24, 2008

It's a bit of a fiddly and convoluted solution, but you could use PD to make a 'scene' for RjDj that doesn't do anything to the signal from the mic, or just boosts it a bit.

Here's a hotwo on making your own RjDj scenes.
posted by jack_mo at 4:50 PM on November 24, 2008

Although for that to work, you'd have to be using headphones with a built-in mic on the cord.

Just to satisfy my curiosity: how is this different to/better than just talking out loud and listening to yourself, with no technology involved at all?
posted by jack_mo at 4:56 PM on November 24, 2008

jack_mo: The mic->headphones loopback gives you a better sense of how your voice sounds to others (as opposed to how it sounds in your own head).
posted by jedicus at 5:52 PM on November 24, 2008

Jeez, sorry; that answer was meant for another phone question a few posts down. I'm an idiot.
posted by chococat at 6:24 PM on November 24, 2008