Visual Basic Threading with More than 2 Threads - vb.net

Question

I am currently trying to produce a sound using a custom beep class. One of the methods of the beep class is to produce multiple octaves of a sound with a given frequency, so one sound is the frequency, another is the frequency * 2, another is the frequency * 4, etc.
I am attempting to use threading to make these all sound together by giving each sound its own thread. However, I notice that it still plays sounds once-at-a-time. I can confirm that the sounds are not interrupting the flow of the program itself, however, so the threading is working in that capacity.
Here is the code I am using. The idea is that for NumOctave times, a new frequency is generated based off the first (and amplitude), and is set to sound in its own thread. However, it appears that the threads are queuing, rather than truly executing asynchronously from each other. What would be the best way to get the intended behavior?
Shared Sub OctBeep(ByVal Amplitude As Integer,
ByVal Frequency As Integer, ByVal NumOctaves As Integer,
ByVal Duration As Integer, ByVal NewThread As Boolean)
Dim threads As List(Of Thread) = New List(Of Thread)
Dim powTwo As Integer = 1
Dim powTen As Integer = 1
For oct As Integer = 1 To NumOctaves
Dim thisOct As Integer = oct
Dim thisThread As New Thread(
Sub()
Dim newFreq, newAmp As Integer
newFreq = Frequency * powTwo
newAmp = Amplitude / powTen
BeepHelp(newAmp, newFreq, Duration)
End Sub
)
thisThread.IsBackground = True
thisThread.Start()
powTwo *= 2
powTen *= 10
Next
End Sub
Here is BeepHelp()
Shared Sub BeepHelp(ByVal Amplitude As Integer,
ByVal Frequency As Integer,
ByVal Duration As Integer)
Dim A As Double = ((Amplitude * 2 ^ 15) / 1000) - 1
Dim DeltaFT As Double = 2 * Math.PI * Frequency / 44100
Dim Samples As Integer = 441 * Duration \ 10
Dim Bytes As Integer = Samples * 4
Dim Hdr() As Integer = {&H46464952, 36 + Bytes, &H45564157,
&H20746D66, 16, &H20001, 44100,
176400, &H100004, &H61746164, Bytes}
Using MS As New MemoryStream(44 + Bytes)
Using BW As New BinaryWriter(MS)
For I As Integer = 0 To Hdr.Length - 1
BW.Write(Hdr(I))
Next
For T As Integer = 0 To Samples - 1
Dim Sample As Short = CShort(A * Math.Sin(DeltaFT * T))
BW.Write(Sample)
BW.Write(Sample)
Next
BW.Flush()
MS.Seek(0, SeekOrigin.Begin)
Using SP As New SoundPlayer(MS)
SP.PlaySync()
End Using
End Using
End Using
End Sub
End Class

Answer 1

I ran into this same issue before writing a speech synthesizer class. There is a difference between Multi-threading(Just moves to a different thread so main program still works) & Parallel Processing(Moves the process to its own processor). You want to look into Parallel Processing instead