def erbs2f(erbs):
    """Converts erb numbers to frequency values

        converts a vector of ERB-rate values
        to the corresponding frequencies in Hz.

        Note that erb values must not exceed 42.79

        Parameters
        ----------
        erb : scalar or array
            Equivalent rectangular bandwidth (ERB) values.
        
        Returns
        -------
        f : scalar or array
            Frequencies, in Hz.
    """
    return 10 ** (erbs / 21.4 + 2.36) - 229
