Skyhawk 172/Cutlass 172
Flight Crew Private
Flight Crew Last 90 Days 60; Flight Crew Total 184; Flight Crew Type 184
Situational Awareness; Communication Breakdown
Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway
Flight Crew Became Reoriented; Flight Crew Executed Go Around / Missed Approach
Human Factors
We were on Ground frequency at taxiway D and 9L doing the run up. I finished the before takeoff checklist and advised Ground of completion of [same]. At this time ground cleared us to switch and monitor the Tower frequency. I complied with clearance and I switched the frequency from ground to North Tower. I started taxiing all the way to the hold short line. We were number one at 9L for departure. When we arrived at hold short line I switched the controls to my instructor. Tower was already giving clearance for takeoff. We assumed it was for us since we were holding short number one. We then [read] back the clearance. Since there was no response from tower we thought that the clearance was for us. [We] then started moving and right after crossing the hold short line we heard on the radio from an aircraft on final saying 'Aircraft on the runway; going around'. My Instructor stopped immediately the aircraft right after hearing an aircraft on the radio. After that; Tower came back on the frequency saying 'thank you' and then 'stop.' Tower told us to turn around and wait behind the hold short line for departure.
After listening to the audio recording it shows that our clearance response was blocked by another aircraft; and because of it tower did not hear our response. At the time we were giving the clearance back on our radio; we did not hear any interference in the transmission. Since we were first for departure and there was no indication of negative clearance we then started to cross hold short line.
C172 instructor and student pilot reported an aircraft went around when they taxied onto the runway in error.