def test_reducing_by_stats(audio_file, out_lib):
    y, sr = sf.read(audio_file)
    y_power = Denoiser.reduce_noise_power(y, sr)
    y_cent_s = Denoiser.reduce_noise_centroid_s(y, sr)
    y_cent_mb = Denoiser.reduce_noise_centroid_mb(y, sr)
    y_mfcc_d = Denoiser.reduce_noise_mfcc_down(y, sr)
    y_mfcc_u = Denoiser.reduce_noise_mfcc_up(y, sr)
    sf.write(out_lib + '/power.wav', y_power, sr)
    sf.write(out_lib + '/cent_s.wav', y_cent_s, sr)
    sf.write(out_lib + '/cent_mb.wav', y_cent_mb, sr)
    sf.write(out_lib + '/mfcc_d.wav', y_mfcc_d, sr)
    sf.write(out_lib + '/mfcc_u.wav', y_mfcc_u, sr)