Building an Audio Spectrum Analyzer
for iPhone

A hands-on tutorial for experienced programmers learning iOS development and audio signal processing from scratch.

Swift SwiftUI AVAudioEngine Accelerate / vDSP FFT

Getting Started

0

Preface & Orientation

What you'll build, prerequisites, C# → Swift quick reference

Arc 1 — The VU Meter

1

Your First iOS App iOS

Xcode project setup, SwiftUI fundamentals, a static placeholder UI
2

What Is Sound? DSP

Sampling, PCM, Nyquist, buffers, RMS, decibels
3

Capturing Audio on iOS Both

AVAudioEngine, mic permissions, AudioEngine.swift, working VU meter
4

Accelerating the Math Both

Apple’s Accelerate framework, vDSP, unsafe pointers

Arc 2 — The Spectrum Analyzer

Finishing Up