This page addresses common issues encountered when using V-Listen and provides step-by-step
solutions. If your issue is not listed here, check the application log in
Windows Event Viewer → Application for detailed error messages.
File and Data Issues
HDF File Will Not Open
Symptom
Error message when opening an HDF file, or the file appears empty.
Possible Causes
The file is a generic HDF5 file, not a V-Listen HDF file (different internal format).
The file is corrupted (incomplete write, disk error).
The file was created by an unsupported schema version.
Solutions
Verify the file source. V-Listen HDF files cannot be opened with h5py or HDFView.
If the file is a Python HDF5 file (.h5), use File → Import → Python HDF instead.
Check the file size; a 0-byte file indicates a failed recording.
No Sound During Playback
Symptom
Time-domain data is loaded and displayed, but pressing Play produces no audio output.
Possible Causes
The system audio output device is muted or disconnected.
The selected playback channel contains ultrasonic or infrasonic content outside the audible range.
The playback volume in V-Listen is set to zero.
The audio driver is in exclusive mode and locked by another application.
Solutions
Check the Windows volume mixer and ensure V-Listen is not muted.
Verify the playback device in Settings → Audio Output.
Check the V-Listen playback volume slider (bottom toolbar).
If the signal is ultrasonic, enable Playback → Frequency Shift to shift it into the audible range.
Calibration Mismatch
Symptom
Measured levels are significantly different from expected values (e.g., 94 dB pistonphone reads 80 dB or 108 dB).
Possible Causes
Incorrect transducer sensitivity entered in channel configuration.
Sensitivity units mismatch (mV/Pa vs. V/Pa, or mV/g vs. mV/(m/s²)).
IEPE power not enabled for an IEPE transducer (low or no signal).
Pistonphone battery depleted (low output level).
Coupler adapter not properly seated on the microphone capsule.
Solutions
Verify the sensitivity value on the transducer calibration certificate.
Confirm the sensitivity unit matches what V-Listen expects (check the unit label next to the input field).
Run a pistonphone calibration using the built-in calibration wizard.
Check that IEPE power is enabled for IEPE transducers in the channel configuration.
Replace the pistonphone battery if the calibration level is unstable.
Acquisition Issues
NI DAQ Buffer Overruns
Symptom
Recording stops with a buffer overrun error, or gaps appear in the recorded data.
Solutions
Reduce the sampling rate or the number of active channels.
Use an SSD instead of an HDD for the recording destination.
Close other applications that may consume disk I/O bandwidth.
Increase the buffer size in Acquisition → NI DAQ → Advanced Settings.
Disable real-time antivirus scanning on the recording folder.
Analysis Issues
FFT Shows Unexpected Peaks
Symptom
Spectrum contains peaks at 50/60 Hz and harmonics, or broadband elevation not present in the physical signal.
Solutions
50/60 Hz hum — check cable shielding, grounding, and physical distance from power sources.
Harmonic distortion — verify the input signal is not clipping. Reduce gain or increase measurement range.
Aliasing — ensure the sampling rate is at least 2.56× the highest frequency of interest.
Spectral leakage — use a Hanning window for continuous signals. Rectangular window is only appropriate for transients fully contained in the block.
V-Listen logs detailed diagnostic information to the Windows Event Viewer under the
Application log source. When reporting issues to support, include the relevant Event Viewer
entries along with the project file and sample data.
Performance Issues
Application is Slow or Unresponsive
Symptom
UI freezes during analysis, slow chart rendering, or long load times.
Solutions
Close unused panels and charts to reduce rendering load.
Reduce the FFT size or number of averages for initial exploration; increase for final analysis.
For large datasets (> 1 GB), use the time selection tool to analyze segments rather than the full recording.
Ensure the GPU driver is up to date for hardware-accelerated chart rendering.
Check available RAM; V-Listen requires at least 4 GB free for typical analyses.
Getting Further Help
Check the Windows Event Viewer (Event Viewer → Windows Logs → Application) for V-Listen error entries.
Include the full error message, project file, and a minimal reproduction dataset when contacting support.
Consult the Glossary if unfamiliar terms appear in error messages or analysis parameters.