Simcenter Testing Solutions Simcenter Testlab Audio Replay and Filtering

Simcenter Testlab



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The Simcenter Testlab Audio Replay and Filtering add-in is used to replay and listen to recordings.  Filters can be applied during the playback to isolate specific frequency ranges and orders.

   1.    Getting Started
   2.    Play from Navigator
   3.    Play from Display
   4.    Replay Range
   5.    Multiple Traces
      5.1  Volume
      5.2  Jump Mode
   6.    Filters
   7.    Overall Level, Order, Colormap Replay
   8.    Replay Speed
   9.    Stereo Replay 

1. Getting Started

To listen and evaluate recordings in Simcenter Testlab, the “Audio Replay and Filtering” add-in can be used. It can be activated by selecting “Tools -> Add-ins” from the main Simcenter Testlab menu as shown in Figure 1.
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Figure 1: Audio Replay and Filtering Add-in is found under “Tools -> Add-ins” from the main Simcenter Testlab menu.

While it is turned on, the Audio Replay and Filtering add-in occupies 36 tokens.  See token licensing article: Simcenter Testlab Tokens: What are they, and how do they work?

2. Play from Navigator

With the add-in turned on, additional capabilities are available.  For example, in the Navigator worksheet, when right clicking on a throughput time file, there is a menu entry called “Audio Replay…” as shown in Figure 2.
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Figure 2: Right click in the Navigator on a throughput file and select “Audio Replay…”.

The Audio replay menu appears as shown in Figure 3.
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Figure 3: Audio Replay and Filtering menu.

The menu has three main sections:
  • Trace list: Shows the time histories selected
  • Playback Buttons: Replay can be started and stopped
  • Filters: Filters can be defined and applied to the data
Any type of time trace can be replayed, not just acoustic.  For example, accelerometers or strain gauges could be replayed.  Sometimes, faults in bearings and other types of problems are easier to hear when playing back an accelerometer that is directly on the object.

3. Play from Display

It is also possible to initiate replay from a Simcenter Testlab display.  After selecting a trace in the display, right click and select “Audio Replay…” selection as shown in Figure 4.
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Figure 4: In Simcenter Testlab display, right click on selected trace and choose “Audio Replay…” menu entry.

When performing replay from a display, the replay menu does not show the time trace as replay from the Navigator.  All other menu functions are the same.

4. Replay Range

A smaller time range of the displayed trace can be replayed.  A smaller range can be selected by dragging the cursors in the display, or by entering values directly in the segment area as shown in Figure 5.
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Figure 5: Use the cursors or enter values in the segment area to select a replay range.

The cursors work as follows:
  • Right Cursor: Changes the range.  Recommend using this cursor first! Use this cursor to narrow the replay range.  Moving the left cursor could cause the right cursor to move out of the display otherwise.
  • Left Cursor: Changes the start position for the replay. Both cursors move together when moving the left cursor.
Sound will replay between the two cursor locations.

5. Multiple Traces

If two or more traces are selected in the display, initiating replay (Figure 6) allows switching between the sounds instantly during playback.
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Figure 6: With two or more traces selected, the Audio Replay menu allows instant switching between two sounds.  

After starting playback, just click between traces in the Playlist menu. This allows two different recordings (for example a baseline sound and a modified sound) to be heard instantly back to back.

5.1 Volume

When replaying two different traces, by default the volume of the two sounds are scaled correctly relative to one another.  

Volume is dictated via the “Options”  button on the right side of the replay menu.  Clicking on the “Options” button opens a menu with a “Replay Range” section as shown in Figure 7.
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Figure 7: Volume of the replay is dictated settings under the “Options” button of the replay menu.

"Range" in this case refers to the amplitude, not the time frame. By default the Replay Range is set to “Auto” for maximum volume.

The “Auto” setting means that the recording volume of the highest level of the recordings is automatically optimized to take the full volume of the sound settings of the computer.  Any other recording’s volume is scaled relative to the recording with the highest level.

By turning off “Auto”, the replay range can be entered manually in decibels.  This is useful if the playback output of the computer has been fixed for calibrated playback.

5.2 Jump Mode

There is a “Jump” setting in the Audio Replay menu that governs how the playback works when switching between recordings (Figure 8):
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Figure 8: Jump mode dictates how the playback behaves when switching between recordings.

The “Jump” settings work as follows, when switching between recordings in the Playlist:
  • No Jump: Playback continues at the same time in the recordings.
  • Reset Jump: Playback starts at the beginning of each recording.
  • Track Jump: Playback continues at the same rpm in the recordings.

6. Filters

There are several icons that can be used to create filters that can be applied during playback (Figure 9).
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Figure 9: Use icons to create filters to be used during playback.
The filter types available include:
  • Lowpass: Passes content below specified frequency.
  • Highpass: Passes content above specified frequency.
  • Bandpass: Passes content between the two specified frequencies.
  • Bandstop: Stops content between the two specified frequencies.
  • Notch: Stops content at the single frequency specified.
  • Orderstop: Stops content at the single order specified. Recording must contain a rpm trace.
  • Orderpass: Passes only content at the single order specified. Recording must contain a rpm trace.
All the created filters can be turned on and off at once by highlighting the filters and using the toggle button (Figure 10):
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Figure 10: All filters can be turned on and off at the same time (highlight rows first) using the toggle button (upper right).
The filters can also be deleted using the X icon and can be saved and retrieved using the file folder icons. Filters can be turned on and off individually.

7. Overall Level, Order, Colormap Displays

Audio playback can be initiated by selecting “Audio Replay…” when right clicking on a overall level, order cut, or other function in a FrontBack display as shown in Figure 11.
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Figure 11: Any function in a FrontBack display can be used to initiate replay. Right click on the data and select “Audio Replay…”.

What time data is used when selecting an overall level or other function?  Processed data and time throughput data are all stored in a single folder as shown in Figure 12
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Figure 12: Processed data and time throughput data are stored together in a run. 
Because they are stored together, when selecting the overall level, or any other calculated function, the software knows where the corresponding time history is located.  It is this time history that gets replayed.  The full frequency content of the time history gets replayed, even if clicking on an order in a Simcenter Testlab display.

Colormap displays can also be used with “Audio Replay…” as shown in Figure 13.
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Figure 13: A colormap display can be used to initiate replay. Right click and select “Audio Replay…”.
Cursors will appear automatically in the display and scroll in sync with the sound being played back.

8. Replay Speed

Sometimes it is useful to slow the playback of sound.  This could be useful if there is a short transient or other short duration sound that is hard to hear.

The playback speed is controlled by clicking on “Original speed” pulldown on the right side of the Audio Replay menu as shown in Figure 14.
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Figure 14: Playback speed is controlled in the Audio Replay menu.
Events like a door slam on a car may consist of multiple transients close together.  Slowing down the playback helps break the sound down.

9. Stereo Replay

Binaural, or stereo, playback is possible:
  • Stereo Channels: If the data is already stored in stereo format, both the right and left ear will play in stereo automatically when selected for playback.
  • Separate Channels: Any two separate channels can be selected to play in stereo with the Audio Replay interface.  This is defined by the user and is not automatic.
Looking at channels stored in a throughput, there are green and red symbols used to indicate if the data is already stereo or not as shown in Figure 15:
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Figure 15: Top – Right and left ear are distinct and separate channels.  Bottom – Right and left ear are stored in a stereo format which is indicated by the green and red symbol.

To play two separate channels as stereo, select the two channels (hold down CONTROL key if needed while clicking) to be played in stereo as shown in Figure 16:
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Figure 16: To play two separate channels in stereo, select them and choose “Audio Replay…”

In the Audio Replay menu, click on the “Stereo” button located in the upper right side just below the Playlist (Figure 17):
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Figure 17: Press the “Stereo” button to play two single channels as stereo.  One channel can be assigned to right and one channel to the left for playback.

Select which channel should be used for the left and right ear during playback and press OK.  The two separate traces in the Playlist will show as one stereo playback entry.

The Audio Replay menu only temporarily identifies the channels as stereo.  To make a permanent change, use the STEREO_MULTIPLEX command in Time Signal Calculator.  More on using the Time Signal Calculator in the knowledge article: Time Signal Calculator Tips!

Some other playback options in Simcenter Testlab and Simcenter Testlab Neo include:
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KB Article ID# KB000129535_EN_US



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