import torch


def hz_to_mel(freqs: torch.Tensor):
    """
    Converts a Tensor of frequencies in hertz to the mel scale.
    Uses the simple formula by O'Shaughnessy (1987).

    Args:
        freqs (torch.Tensor): frequencies to convert.

    """
    return 2595 * torch.log10(1 + freqs / 700)