Back-channel Trainer (Win32 API)

This version is no longer being mantained. For the most recent version of the trainer, check this page.

Summary

This software was developed to train learners to produce back-channels at appropriate
times in a conversation. The program scores the user depending on the timing and
frequency quality of her backchannel productions.

Requirements: Windows 2000/XP, microphone and speakers (headset recommended).

Download Back-channel Trainer v1.73

Click here to download the installer for Windows 2000/XP
Click here to download the source code (Visual Studio 6.0 VC++)

Change History

 1.73 Bugfix: Timing quality score was incorrect
      Added percentage signs to score
 1.72 Bugfix: Icon didn't display on the ALT-TAB menu. 
      Changed overall score to frequency and timing quality product
      Added learner feedback
      Bugfix: Cue light stayed on if stopped when on
      Bugfix: Multiple conversation loading is now more reliable
      Bugfix: Tab order in settings window is now correct
      Visual cue disabled at start
      Bugfix: Playback now stops automatically after dialog end
      Improved sensitivity slider step size (was too big)
      Bugfix: The process sometimes refused to quit
      Bugfix: The Trainer now shows in the taskbar
 1.56 Fixed an infrequent timing bug
 1.55 Cue display timing bug fixed
 1.51 Tutorial launcher added to the GUI
 1.5  Alternate speech detection method added
 1.4  Cue light added + misc. bug fixes
 1.1  Fixed display bug that prevented BC Detect light
 from turning on, fixed intermittent incorrect score display
 1.0  Implemented a more accurate scoring weight
 0.8  Fixed timing issues related to streaming wavefile
 directly from disk
 0.75 Better response is achieved by performing streaming by
 a callback, instead of in the main message loop
 0.7  Enhanced playback code to directly stream from disk
 eliminating wave file size restriction.
 0.6  Changed all code from MFC/C++ to WinAPI/C
 0.2a RMS level display works correctly
 0.1a Performs rudimentary audio I/O from/to memory buffers

Installation Instructions

Download and run the installation program. The trainer application will appear
in your Windows Start menu under "Back-channel Trainer" after installation.
Open the Windows Volume Control application (to open it, click the Windows Start Menu
button and navigate to All Programs -> Accessories -> Entertainment -> Volume Control)
While having the Volume Control application open, make sure that the Wave output is not muted and
that the volume fader is at 100%.
In the Volume Control application, click on the Options menu and click Properties.
When the properties window is displayed, click the Recording radio button and click OK. Make sure
that the Input fader is unmuted and at 100%.

Note: The program will play back and record from the default audio device. To change the default audio
device, you can go to Control Panel and click on the Sound devices icon. You may need to restart the
trainer to enable the newly configured devices.

Interface Changes in v1.7

Score and learner feedback is displayed after the conversation ends or when
the user presses the "Stop" button
Output log window was removed

Interface Changes in v1.56

The cue light is bigger to match the tutorial.
The red indicator in v1.1 has been moved to the upper part of the level
display - it was too distracting to users when the cue light was activated.
A button for opening the tutorial has been added.
When the alternate detection method is selected, the level segment displays
the average level instead of the peak level.

Usage

Upon installation, the shortcut to the Back-Channel Trainer will appear in your Windows start menu.

(1) Run the Trainer and you will see the initial main window.

(2) Before you begin training, you must load a conversation. Load a conversation by clicking on
the "Load..." button. Two conversations have been included in the default installation. These conversations
can be found in your disk drive in the following path: C:\Program Files\Backchannel Trainer\Conversations
(if you installed to a different drive, substitute the C: for the right drive).

(3) Select a WAVE file and click Open.

(4) Select the corresponding BC file and click Open.

(5) The Start button is enabled and you can start training.

Adjusting Settings

The Settings window allows you to adjust some run time parameters.

Tolerance. This value defines the time window in which back-channels will be
counted as "Hits", and not as "Semi-Hits". The window range begins from the time that
the cue starts until that time plus the tolerance value. For example, if we have a 1400ms
tolerance, and a cue occurs at 3.00 seconds, a back-channel will be counted as a
"Hit" if it is produced within [3.00, 4.40] seconds.

After a BC, freeze scoring for. Long user utterances like a long "Ok" or repairs such as
"O-Ok" can span several hundredths of a second. To avoid counting these long utterances
more than once, we "freeze" the scoring when an utterance is detected for a preset time
of 900ms. In order for two backchannels to count as two backchannels, they would have
to be produced more than 900ms apart.

Enable visual cue. This toggle enables or disables the visual cue displayed on the
main screen.

Alternate detection method. This is a new detection method is being tested for dealing
with noisy headsets, currently the utterances have to be about 300ms long to be discriminated
from noise. This feature is still under development.

Previous Versions

Back-channel Trainer v1.56

Click here to download the installer for Windows 2000/XP
Click here to download the source code (Visual Studio 6.0 VC++)

Back-channel Trainer v1.1

Click here to download the installer for Windows 2000/XP
Click here to download the source code (Visual Studio 6.0 VC++)

Questions

Email Rafael Escalante to the following address: rescalante at utep dot edu.