Building a Real-Time Audio Amplifier on Android: Microphone, Processing, and Latency

#android #kotlin #mobiledev #audio

Why Real-Time Audio Amplification Is Harder Than It Looks

I wanted to build a simple Android app that could help people hear surrounding sounds more clearly using a phone and a pair of headphones or earbuds.

The basic idea sounds simple:

Phone microphone → audio processing → headphones

But once you try to make it useful in real time, several interesting engineering problems appear.

The first step is capturing audio from the Android microphone.

The captured audio then needs to be processed before being sent to the output device.

A simplified pipeline looks like this:

Microphone
↓
Audio Capture
↓
Gain / Amplification
↓
Audio Processing
↓
Output
↓
Headphones / Earbuds

I built these ideas into Sound Amplifier: Hear Better, an Android app I'm currently developing.

If you'd like to try it:

I'd be interested in hearing your feedback about latency, audio quality, and the overall listening experience.