How to use the psychtoolbox.audio.verbosity function in psychtoolbox

####################################################################
    ############## 1st test: play some tones ###########################
    ####################################################################

    # Length of audio vector - 1 secs of playback:
    n_samples = 1 * Fs

    # Build sinewave:
    a = np.sin(np.linspace(0, 2 * pi * f * n_samples / Fs))

    # Replicated into two rows - One row for each stereo-channel, ie.
    # m'th row == m'th channel, n'th column = n'th sample frame:
    stereowav = [a, a]

    audio.verbosity(5)

    # Open audio device: Default audio device, default opmode (playback), default
    # latency/timing-precision (low-latency, high precision), sample rate Fs,
    # stereo (2) channel output:
    stream = audio.Stream(freq=Fs, channels=2)
    stream.volume = 0.5  # PsychPortAudio('Volume', pahandle, 0.5)

    if True:
        # Fill in audio matrix for playback: columns = audio channels, rows = samples
        # Do it step-by-step for performance testing:
        stereowav = np.array(stereowav, order='f')
        # print('Type', type(stereowav), 'Shape', stereowav.shape, 'Datatype',
        #       stereowav.dtype, 'Order', stereowav.flags);
        stereowav = np.transpose(stereowav)
        # float32 is a tad faster than the default float64:
        stereowav = stereowav.astype('float32')

defaultOutput = audioDevice


travisCI = bool(str(os.environ.get('TRAVIS')).lower() == 'true')
logging.info("Loaded psychtoolbox audio version {}"
             .format(audio.get_version_info()['version']))

# ask PTB to align verbosity with our current logging level at console
_verbosities = ((logging.DEBUG, 5),
                (logging.INFO, 4),
                (logging.EXP, 3),
                (logging.WARNING, 2),
                (logging.ERROR, 1))
for _logLevel, _verbos in _verbosities:
    if logging.console.level <= _logLevel:
        audio.verbosity(_verbos)
        break

def init(rate=48000, stereo=True, buffer=128):
    pass  # for compatibility with other backends


def getDevices(kind=None):
    """Returns a dict of dict of audio devices of specified `kind`

    The dict keys are names and items are dicts of properties
    """
    devs = {}
    if travisCI:  # travis-CI testing does not have a sound device
        return devs
    else:
        allDevs = audio.get_devices(kind)