def preproc(path, sr=<NUM_LIT>, alpha=<NUM_LIT>):
oldsr, sig = wavfile.read(path)<EOL>try:<EOL><INDENT>sig = sig[:, <NUM_LIT:0>]<EOL><DEDENT>except IndexError:<EOL><INDENT>pass<EOL><DEDENT>if False and sr != oldsr:<EOL><INDENT>t = len(sig) / oldsr<EOL>numsamp = int(t * sr)<EOL>proc = resample(sig, numsamp)<EOL><DEDENT>else:<EOL><INDENT>proc = sig<EOL>sr = oldsr<EOL><DEDENT>if alpha is not None and alpha != <NUM_LIT:0>:<EOL><INDENT>proc = lfilter([<NUM_LIT:1.>, -alpha], <NUM_LIT:1>, proc)<EOL><DEDENT>return sr, proc<EOL>
Preprocess a .wav file for later processing.  Currently assumes a
    16-bit PCM input.  Only returns left channel of stereo files.

    Parameters
    ----------
    path : str
        Full path to .wav file to load.
    sr : int, optional
        Sampling rate to resample at, if specified.
    alpha : float, optional
        Alpha for preemphasis, defaults to 0.97.

    Returns
    -------
    int
        Sampling rate.
    array
        Processed PCM.