Another slightly more experimental looking synth arrives for the iOS.
iOS Audio Processing Graph Demonstration
“An audio processing graph is a Core Foundation opaque type, AUGraph, that you use to construct and manage an audio unit processing chain. A graph can leverage the capabilities of multiple audio units and multiple render callback functions, allowing you to create nearly any audio processing solution you can imagine.” – From Apple’s “Audio Unit Hosting Guide For iOS”
AudioGraph is a superset of Apple’s MixerHost application.
Features include:
- Mono and stereo mic/line input
- Audio effects including:
- Ring modulator
- FFT passthrough using Accelerate vDSP framework
- Real-time pitch shifting and detection using STFT
- Simple variable speed delay with using a ring buffer
- Recursive moving average filter with variable number of points
- Convolution example with variable filter cutoff frequency
- Stereo level meter
- Synthesizer example – sine wave with an envelope generator
- iOS 5 features (from Chris Adamson) including:
- MIDI sampler audio unit
- file player audio unit
- audio unit effects
- Runs on iPad, iPhone, and iPod-Touch
- Open source
- Music by Van Lawton
- Everything from MixerHost
Requirements:
- A device that runs iOS 5.x
- Headphones.
Instructions:
Launch the app and press Play.
Source code, documentation, support:
http://zerokidz.com/audiograph
Credits:
This project is derived from work by:
- Chris Adamson
- Stefan Bernsee
- Michael Tyson
- Stephen Smith
- Contributors to the Core-Audio mailing list
- Contributors to stack overflow.com
- Apple’s iOS developer program,
The app is free. 
