Flight Crew Multiengine; Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument
Flight Crew Last 90 Days 120; Flight Crew Total 1100; Flight Crew Type 1080
Human-Machine Interface; Situational Awareness; Distraction; Communication Breakdown
Aircraft Equipment Problem Less Severe; Conflict NMAC
General None Reported / Taken
Environment - Non Weather Related; Human Factors
Conducting flight training at ZZZ. There was a near miss involving myself and another plane on final.Prior to the incident; radio traffic around ZZZ became distracting for both my student and I while we were practicing steep turns; so I turned the volume down to where I could still hear the other traffic; but could focus on my lesson.Conducting left traffic Runway XX; on the takeoff roll; I instructed my student to apply take off power; and climb out at 85 kts once gear was retracted and propeller set to 2500 RPM. We turned left crosswind 500 AGL; then left downwind for [Runway] XX. Proper radio calls were made on left crosswind and left downwind. Visually scanning the area; I did not see any other traffic. Midfield downwind landing gear was set to the down position; green gear light verified. Once abeam the numbers [Runway] 21; power was reduced to 2100 RPM; flaps 10 degrees; and 75 kts established. 45 degrees off our landing point; left base radio call was established; then left base was turned; and 20 degrees of flaps established. Final call and turn was made; 30 degrees flaps and a normal landing.Once parked and shut down; a gentleman walked briskly up to my plane and informed me that we had just turned final 'a quarter mile in front of him'. He also explained he heard my radio calls; and was responding. I had not heard him so I inspected my volume knob for com 1; finding it turned down too far to have heard him. I apologized sincerely; and will ensure that volume remains where I can hear other pilots at all times.
C172 flight Instructor reported an NMAC during approach to landing as a result of turning down the radio volume and not hearing an inbound aircraft's radio transmissions.