Small Aircraft; Low Wing; 1 Eng; Retractable Gear
Flight Crew Commercial; Flight Crew Instrument
Flight Crew Last 90 Days 13; Flight Crew Total 780; Flight Crew Type 350
Communication Breakdown; Distraction; Physiological - Other; Troubleshooting; Situational Awareness
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented
Environment - Non Weather Related; Human Factors
I fly X type missions; for which I'm wearing a mask; which I knew harms the sealing of my active noise reduction headset (and as a result reduces the sound quality; bringing in some ambient noise). It was not until yesterday that I realized how disruptive this is.I was flying on the last leg of my IFR flight plan; from ZZZ to ZZZZZ (from there to my destination - ZZZ1). ATC called me and said something about heading 290 with ZZZZZ in it; I assumed they're telling me I need to fly 290 to ZZZZZ (and from there proceed as usual). That's what I did; ATC got (rightfully) upset and told me that I was asked to fly 290; which I then did and later cleared for a visual approach to Runway XX at ZZZ1.Listening to the recording on liveatc.net; I could clearly hear the ATC telling me to depart ZZZZZ at heading 290. That 'depart' is the one piece of the puzzle I didn't hear during the flight.On my way back - no passengers; no mask - all of a sudden ATC sounded much clearer. It made obvious to me this has to change; and I need to find a mask that does not interfere with my headset.
Single pilot reported unable to understand the Controller's instruction clearly due to the pilot's face mask interfering with the over ear headset.