Isolation of the QC15 (green trace), the Audio-Technica ATH-ANC9 in NC mode 1 (purple trace), and the Polk UltraFocus 8000 (blue trace), right channel, measured with pink noise at a reference level of 75 dB at 1 kHz. Numbers below 75 dB indicate a reduction in leakage of interior sound into the headphones. Actual results may vary depending how well the earpieces fit your ears.
