use vlc to trancode wav to mp3

New-VLC_transcode.ps1

<#
.link
   https://wiki.videolan.org/VLC_HowTo/Transcode_multiple_videos/
#>
$outputExtension = ".mp3"
$bitrate = 160
$channels = 2

foreach($inputFile in get-childitem -recurse -Filter *.wav)
{ 
  $outputFileName = [System.IO.Path]::GetFileNameWithoutExtension($inputFile.FullName) + $outputExtension;
  $outputFileName = [System.IO.Path]::Combine($inputFile.DirectoryName, $outputFileName);
  
  $programFiles = ${env:ProgramFiles(x86)};
  if($programFiles -eq $null) { $programFiles = $env:ProgramFiles; }
  
  $processName = $programFiles + "\VideoLAN\VLC\vlc.exe"
  $processArgs = "-I dummy -vvv `"$($inputFile.FullName)`" --sout=#transcode{acodec=`"mp3`",ab=`"$bitrate`",`"channels=$channels`"}:standard{access=`"file`",mux=`"wav`",dst=`"$outputFileName`"} vlc://quit"
  
  start-process $processName $processArgs -wait
}