VoiceCommands.psm1

Add-Type -TypeDefinition @'
using System.Runtime.InteropServices;
[Guid("5CDF2C82-841E-4546-9722-0CF74078229A"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
interface IAudioEndpointVolume
{
    // f(), g(), ... are unused COM method slots. Define these if you care
    int f(); int g(); int h(); int i();
    int SetMasterVolumeLevelScalar(float fLevel, System.Guid pguidEventContext);
    int j();
    int GetMasterVolumeLevelScalar(out float pfLevel);
    int k(); int l(); int m(); int n();
    int SetMute([MarshalAs(UnmanagedType.Bool)] bool bMute, System.Guid pguidEventContext);
    int GetMute(out bool pbMute);
}
[Guid("D666063F-1587-4E43-81F1-B948E807363F"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
interface IMMDevice
{
    int Activate(ref System.Guid id, int clsCtx, int activationParams, out IAudioEndpointVolume aev);
}
[Guid("A95664D2-9614-4F35-A746-DE8DB63617E6"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
interface IMMDeviceEnumerator
{
    int f(); // Unused
    int GetDefaultAudioEndpoint(int dataFlow, int role, out IMMDevice endpoint);
}
[ComImport, Guid("BCDE0395-E52F-467C-8E3D-C4579291692E")] class MMDeviceEnumeratorComObject { }
public class Audio
{
    static IAudioEndpointVolume Vol()
    {
        var enumerator = new MMDeviceEnumeratorComObject() as IMMDeviceEnumerator;
        IMMDevice dev = null;
        Marshal.ThrowExceptionForHR(enumerator.GetDefaultAudioEndpoint(/*eRender*/ 0, /*eMultimedia*/ 1, out dev));
        IAudioEndpointVolume epv = null;
        var epvid = typeof(IAudioEndpointVolume).GUID;
        Marshal.ThrowExceptionForHR(dev.Activate(ref epvid, /*CLSCTX_ALL*/ 23, 0, out epv));
        return epv;
    }
    public static float Volume
    {
        get { float v = -1; Marshal.ThrowExceptionForHR(Vol().GetMasterVolumeLevelScalar(out v)); return v; }
        set { Marshal.ThrowExceptionForHR(Vol().SetMasterVolumeLevelScalar(value, System.Guid.Empty)); }
    }
    public static bool Mute
    {
        get { bool mute; Marshal.ThrowExceptionForHR(Vol().GetMute(out mute)); return mute; }
        set { Marshal.ThrowExceptionForHR(Vol().SetMute(value, System.Guid.Empty)); }
    }
}
'@
 -ErrorAction SilentlyContinue

function Out-Voice
{
    param
    (
        [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [System.String[]]
        $Text,

        [ValidateSet('Male', 'Female')]
        [System.String]
        $Gender = 'Female',

        [cultureinfo]
        $VoiceCulture = 'en-us',

        [int16]
        [ValidateRange(-10,10)]
        $Rate = 0
    )

    begin
    {
        $synth = New-Object System.Speech.Synthesis.SpeechSynthesizer
        $synth.SelectVoiceByHints($Gender, 30, $null, $VoiceCulture)
        $synth.SetOutputToDefaultAudioDevice()
        $synth.Rate = $Rate
    }
    
    process
    {  
        foreach ( $t in $text)
        {
            $synth.Speak($t)
        }
    }

    end
    {
        $synth.Dispose()
    }
}

function Set-Speaker
{    
    param
    (
        [Parameter()]
        [ValidateRange(0.0,1.0)]
        [double]
        $Volume,

        [Parameter()]
        [bool]
        $Mute = $false
    )

    Write-Verbose -Message ("Setting speaker to {0:p} volume, muted: {1}" -f $Volume, $Mute)

    if ($Volume) { [Audio]::Volume  =$Volume}
    [audio]::Mute = $Mute

}

New-Alias -Name ov -Value Out-Voice -Description "Alias for voice cmdlet Out-Voice" -Force