This is not so simple, even if you just want to change the tempo of the whole WAV record. As far as I can see, .NET FCL does not provide a ready-to-use library for playing a record at arbitrary speed. You need to go to a lower level, with the Windows multimedia library. This CodeProject article will give you a good idea on what's involved:
Playing .WAV files using the Windows Multi-Media Library[
^].
If you want all that with .NET, you would need to wrap the Windows multimedia subsystem ("winmm.dll"). At least one such open-source wrapper is already created for you:
http://winmm.codeplex.com/[
^].
For detailed MSDN documentation, please see:
http://msdn.microsoft.com/en-us/library/windows/desktop/dd743883%28v=vs.85%29.aspx[
^],
http://msdn.microsoft.com/en-us/library/windows/desktop/dd743606%28v=vs.85%29.aspx[
^].
All of the above is currently considered as "legacy API". You can also check out more up-to-date Microsoft API, but it only can be used in Windows 8 or Windows Server 2012:
http://msdn.microsoft.com/en-us/library/windows/desktop/dd370802%28v=vs.85%29.aspx[
^].
—SA
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