Contents - Index - Next

Working with Audio Files

Standard File Open/Save/SaveAs Dialog boxes are used to allow you to locate files on your system.  Only the  .WAV format is currently supported, however you may import raw data files from other acquisition systems using the File Import command.   The program also supports "Drag and Drop" from the Windows File Manager (refer to Winfile.hlp if you are unfamiliar with this feature).

Once a file is opened, or recording has started, the sampling rate and format cannot be changed.  You must first close the file.  This is because a .WAV file format requires a constant sampling rate and format throughout the entire file.

When the mode is changed to Real-Time, the current file will be closed and you will be prompted to save it if necessary.

The amount of memory required for each minute of audio varies widely depending upon the sampling rate and sampling format.  Some typical values for mono recording are shown below (multiply the values by 2 for stereo recording):

Sampling Rate (Hz)      Sampling Precision (bits)      Bytes/Minute
      11,025                                                    8                                                  661,500 
      11,025                                                   16                                              1,323,000
      22,050                                                    8                                               1,323,000
      22,050                                                   16                                              2,646,000
      44,100                                                    8                                               2,646,000
      44,100                                                   16                                              5,292,000
      44,100                                                   24                                              7,938,000
      96,000                                                   16                                            11,520,000
      96,000                                                   24                                            17,280,000

Continuous Recording Capability
Wave files can store up to 2 GB of data in a single file (the corresponding time depends upon the sampling format).  When this limit is reached, the program will momentarily stop recording, save the file and then start recording again in a new file.  If the file is does not yet have a name, the program will give it a name using the computer date and time.  The file will be stored in the \wave folder as specified in the <File><Set Paths> dialog.  This feature applies to the hard disk recording mode only.

Example: c:\speclab\wave\recording_2002_11_26_102011.wav                     
(in this example the date and time were 10:20:11 Nov, 26 2002 when the file was saved)

See also:  Recorder Mode , Importing Files, Exporting Files, Cut/Copy/Paste commands