In-ear monitors, earphones and noise-attenuating earplugs are provided with a vent to improve insertion, removal and wearing comfort, and to protect delicate audio drivers from excessive pressure excursions. The vent is fitted with a pressure-management material such as a viscoelastic open-cell foam to control the rate at which air can pass through the vent. The pressure-management material permits tuning of the vent to achieve acoustically flat attenuation of ambient sound.