def erb_bandwidth(fc):
    """Bandwidth of an Equivalent Rectangular Bandwidth (ERB).

    Parameters
    ----------
    fc : ndarray
        Center frequency, or center frequencies, of the filter.

    Returns
    -------
    ndarray or float
        Equivalent rectangular bandwidth of the filter(s).

    """
    # In Hz, according to Glasberg and Moore (1990)
    return 24.7 + fc / 9.265