Cochclear Implant and Hearing Loss Simulator
AngelSimTM (TigerCIS)
Hints & Tips
© Emily Fu Foundation
Secrets inside AngelSim

Customized corner frequency for the bandpass filters (.fil)

Format: Each row will have two numbers. Left is the low corner frequency and right is the high corner frequency. Depending on the number of channels, the number of rows should be same as the number of channels. The following shows the customized filters for the 4-channel processor. Analysis and carrier filters have the same format. File name: example.fil 200 800 800 1500 1500 3000 3000 6000

Customized MAP for speech processors (.map)

Format as follows: channel_number peak_number analysis_low_cut analysis_high_cut analysis_slope envelope_cut envelope_slope carrier_low_cut carrier_high_cut carrier_slope carrier_type (0/1) File name: example.map 4 4 100     500  48  200  24   100   500 6 0 500   1000  48  200  24   500 1000 6 0 1000 2000  48   20  24  1000 2000 6 1 2000 4000  48   20  24 2000  4000 6 1
Customized Filter or MAPs for Speech Processors (Step 4 in the procecessor setting of the program) Options and Others
The program can be used to simulate the sound via cochlear implant or due to hearing loss. The selection of cochlear implant simulation or hearing loss simulation is determined by the setting in Step 1. If hearing loss simuator is selected, then hearing threshold should be set by clicking the Audiogram button nearby.
The program can change the tempo and/or pitch of the existing or recorded sound in real-time. To change the tempo (speaking rate) or pitch, click the “Tempo and Pitch” in the bottom to enable the function and set the appropriate parameters.
The program also allow to generate noisy speech of the existing quiet sounds in real-time. To generate noisy speech, click the “Background Noise” button in the button to enable the function and set the appropriate parameters. The parameters include the noise type and the signal-to-noise ratio etc.
Real-Time Processing
Real-time processing is a fun tool to demonstrate how hearing loss or cochlear implant will affect the real- life conversation. Real-time processing is easy. Just setup the parameter for the simulation (cochlear implant or hearing loss), then click the button “Start Real-Time” in the right bottom of the program. If you want to stop the real-time processing, simply click the button “Stop Real-Time” button.
How to Use Video
This video is to show how to use AngelSim: a versatile cochlear implant and hearing aid simulator. The program allows the user to load, download, and record various speech and music signals and process the signals according to the vocoder processing parameters and hearing thresholds. The program also can generate noisy speech real time based on the clean speech and desired signal-to-noise ration as well as the noise type. The program can simulate various types of cochlear implants, including bilateral and bimodal cochlear implant processing. AngelSim also can simulate the speech signal due to different amount of hearing loss according to the audiogram.
How to use Audiogram-based Hearing Loss Simulation?
It is very straightforward to simulate hearing loss with a specific audiogram. Here is the step; Step 1: Run “AngelSimTM” program. Step 2: After the program is running, Select “Hearing Loss Simulator” Processing; Step 3: Clicking <<Audiogram>> button to set the hearing thresholds in seven different pure tone freuqnecies (ranging 125 Hz - 8000 Hz). A figure also shows how the hearing loss will affect different sounds, including speech signals in the so-called “speech banana”. Step 4a (offline processing): Load the speech signals or sounds you want to process, or click the blue button to record your own voice.  Step 4b (real-time processing): Click the “Start Real-Time” button to start the real-time simulation. The computer will record your original voice but the speaker of the computer will play the degraded speech signals. Step 5 (offline processing): Click the “Start Simulation” button in the right to process the loaded signal. Then click the “Play Simulated Sound” to listen to the degraded speech signals due to the specfied hearing loss.