I use this code for trim audio signal
private void button1_Click(object sender, EventArgs e)
{
string ifile = @"E:\Temp\a1.wav";
string ofile = @"E:\Temp\a3.wav";
Process p = new Process();
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardError = true;
p.StartInfo.FileName = "C:\\Program Files (x86)\\sox-14-4-1\\sox.exe ";
p.StartInfo.Arguments = ifile + " " + ofile + " silence 1 0.1 1% -1 0.1 1%";
p.Start();
p.BeginErrorReadLine();
p.BeginOutputReadLine();
}