Setting IF function to speak a sentence

mctribeiro 

Does A1 contain any formula which gets calculated based on other cells?

If yes, you can use the Calculate Event to speak the predefined text. To do so, right click on Sheet Tab --> View code --> and paste the code given below into the opened code window.

Private Sub Worksheet_Calculate()
If Range("A1").Value > 100 Then
    Application.Speech.Speak "Congratulation!! You reached your goal!"
End If
End Sub

If you manually change the cell A1, replace the above code with the Change Event code...

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.CountLarge > 1 Then Exit Sub
If Target.Address(0, 0) = "A1" Then
    If Target > 100 Then
        Application.Speech.Speak "Congratulation!! You reached your goal!", True
    End If
End If
End Sub

The attached contains two sheets named "Calculate Event" and "Change Event" for you test the above codes.

If this is not what you are trying to achieve, please upload a sample workbook and explain that how do you want it to work.