This app performs separate simulations of acoustic hearing loss and cochlear implant processing. These simulations process the audio input from the iOS device in real-time.

In the acoustic hearing loss simulation, a user can achieve custom spectral filtering based on a listener's audiogram. Six presets are also provided of common audiogram functions. A dynamic range compressor is included, along with a frequency smearing algorithm to flatten the signal's spectrum and perform subtle pitch modulation.

In the cochlear implant simulation, a filterbank vocoder is implemented. The number of frequency bands is selectable, along with the carrier signal (noise or sine wave vocoder), the frequency divisions (Logarithmic or Greenwood function), and the overall bandwidth. Electric-only and "hybrid" acoustic-electric cochlear implants are modeled. Several monaural and binaural stimulation options are selectable.

HEADPHONES AND SENNHEISER SMART AMBEO HEADSET
This app was created as part of the Sennheiser Developers Program for the Smart AMBEO Headset. The app is capable of processing a stereo input signal, taking advantage of the "augmented reality" features of the headset. The app is also fully-functional using a conventional set of headphones with a mono microphone input. It is highly recommended to use headphones of some type with the app.

FOR RESEARCH AND EDUCATIONAL PURPOSES
The intended use of the app is for auditory perception research. The app may have additional educational purposes related to hearing loss. The app should not be used for medical purposes.

INFORMATION
Resources related to the app are available at: hackaudio.com