ListenAid

ListenAid - precise, clean & fast audio spectrum analysis.

Turn your iPhone, iPad, or Mac into an easy to read and beautifully intuitive high-precision audio analyzer.

ListenAid is a professional-grade FFT Real-Time Spectrum Analyzer (RTA) and Spectrogram designed for audio engineers, acoustic consultants, musicians, and students. Built entirely on Apple’s Accelerate framework and Metal graphics, it delivers incredibly fluid, high-resolution analysis.

Whether you are tuning a PA system, analyzing room acoustics, or visualizing the harmonic content of an instrument, ListenAid provides the tools you need to visually interpret what you can hear.

HIGH-PERFORMANCE VISUALIZATION
- Metal-Accelerated Graphics: Experience a silky-smooth 60/120 fps display that visualizes audio data in real-time without draining your battery.
- Hybrid View: View the instantaneous FFT spectrum and the scrolling Spectrogram history simultaneously.
- Gestures: Pinch to zoom frequency and amplitude axes independently. Double-tap to reset.

ADVANCED DSP ALGORITHMS
- Standard FFT: Fast Fourier Transform with adjustable buffer sizes (up to 65,536 points).
- Multi-Resolution Spectrogram: Divides the Spectrum into three bands with individual time and buffer resolutions
- CQT, QTAM & CWT: Variable-Q and Continuous Wavelet Transforms for musically relevant analysis.
- Transfer Function: Compare a live signal against a reference signal (Dual-Channel Analysis).

PROFESSIONAL AUDIO ROUTING
- Multi-Channel Support: Fully supports external USB audio interfaces. Select specific input channels for measurement and reference.
- High Sample Rates: Supports hardware sample rates up to 384kHz (and higher, hardware dependent) for high-resolution analysis.
- Smart Bluetooth: Intelligently manages Bluetooth profiles to ensure high-quality monitoring without degrading input quality.

SYSTEM TEST & TOOLS
- Signal Generator: Built-in low-distortion Sine Wave generator.
- Loop Player: Playback your own test loops or music directly from the app to test system response.
- Cursor Mode: Inspect specific frequencies with a cursor showing Hz, dB, Musical Note, and Cents deviation.
- Peak Tracking: Automatically detect and track the strongest frequencies with high-precision interpolation.

REMOTE (via MCF)
- Control one app remotely via another instance of the app - walk the room with your mobile, controlling your laptop/iPad
- Trigger loops, sweep a sine, toggle L/R-Solo, or invert polarity remotely while walking the room.

TECHNICAL SPECIFICATIONS
- True dual channel simultaneous independent real-time FFT
- Window Functions: Hanning, Hamming, Blackman, Flat-Top.
- Averaging Modes: RMS, Exponential, Peak Hold, Off.
- Overlap up to 256x
- Smoothing up to 1/96 Octave
- Resolutions: FFT sizes from 256 to 65k.
- Scales: Logarithmic (Hz) and Linear (Musical Note/Piano Roll).
- Color Maps: Greyscale, Inverted, Lava, Orange & Teal, Infrapink

WHO IS THIS FOR?
- Live Sound Engineers: Ring out feedback and tune systems using the built-in generator and transfer function.
- Studio Engineers: Visualize the frequency spectrum of your mix in high detail.
- Musicians: Use the precise Note/Cents cursor for instrument intonation.
- Educators: Visualize sound waves and harmonics in the classroom.

Privacy Policy: ListenAid processes all audio data locally on your device. No audio is ever recorded or transmitted to the cloud.