Do I need or want the passive ambient feature for my UE Pro Custom In-Ear Monitors?

The passive ambient feature allows environmental or outside noise to mix in with the music. Noise Isolation is reduced from the 26dB to 12dB. This feature is designed primarily to aid professional stage musicians transitioning from traditional wedge speakers to in-ear monitors. Once an artist becomes comfortable with In–Ear Monitors, the ambient port is sealed. Our experience is less than 5% of our artists use this feature.