Transport Mode-Cancels out up to 95% of engine noise to give you a more restful journey Outdoor Mode-Reduces the din of cars driving past and blocks out the noise of the wind Indoor Mode-Adjust to suit quieter locations while still blocking out distracting sounds. According to regulations, the maximum volume of headphones should not exceed 100dB. In order to protect your hearing, Life Q30 maximum volume has been set to around 95dB. It is recommended that you do not listen to excessively loud volumes for long periods of time. For optimal noise cancellation, make sure the earcups create a tight seal around your ears. Playtime varies according to volume and audio content.