Date: 201711
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ; Tower ZZZ
Aircraft component: Air/Ground Communication
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown
Second reporter function: First Officer; Pilot Flying
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: I was the Pilot Flying (PF) and we had been cleared off the Arrival and direct to with a descent to 3000 feet. Everything had been normal until we were cleared for the approach. An issue affected our ability to communicate with ATC (transmitting) and each other (via the intercom). We were able to accept a visual approach clearance with the TRACON about 10 miles from the airport at an altitude of roughly 3000'. However; at this point; we lost the transmit function on both our COMs and it remained unclear whether ATC could hear us. When we both pressed the PTT; the radios went silent despite the 'TX' being present on the radio page of the MCDU. We also could not hear each other over the intercom; but we could hear ATC without issue. The approach controller made several attempts to hand us off to tower; but apparently never heard us. We slowed the aircraft for a visual approach to [the] runway as we continued to resolve the issue. As we configured for landing; we attempted to use the hand mics; as well as; all available PTTs and COM 2 to regain communication. We also reset our O2 mask mics; but the problem continued. The tower controller began calling us as we crossed over the FAF. After establishing the approach; we continued our attempts to reach ATC and Fist Officer (FO) alertly began squawking 7600.The tower made several attempts to clear us to land and we eventually acknowledged our landing clearance by flashing our landing lights and pressing IDENT. Again; this all happened within 10 miles of the airport and left us little time to problem solve. Adding to the frustration; our inability to hear each other made it difficult to complete normal approach calls. We accomplished the Landing Checklist as I established the aircraft on a stabilized approach. However; in our attempts to troubleshoot the communication issue; I neglected to notice the flap handle sitting between 4 and 5. At roughly 700'; we received an aural alert 'TOO LOW; FLAPS'. Our FO quickly tapped the flap handle into the detent and the flaps traveled to the 5 position. After a brief discussion; I elected to continue the approach because we could not communicate a go around to ATC and I was unclear how we would explain our situation as we attempted to return to the field. Additionally; the aircraft was established on speed/profile for a night; visual approach to a long runway in VMC conditions and would ultimately land with the flaps at 5. After a normal/routine landing; we cleared the runway and ATC could now make out some of our transmissions. I still had difficulty hearing via the intercom or when the mic was keyed; but we complied with our taxi instructions and canceled the 7600 squawk at the tower's request. After shutting down at the gate and completing the Parking Checklist; we made several radio checks on COM1 and COM2 using each of the available mics. At this point; the issue had completely disappeared and we were able to communicate clearly using each PTT and mic. I still entered the discrepancy in the aircraft logbook and contacted dispatch and maintenance control to make them aware of the problem.As a side note; Tower informed us that we were the second [company] aircraft to arrive this evening with radio issues.The best way to prevent these fixation issues would be to remain vigilant and follow SOP. I personally neglected the golden rule of aviating before communicating as I attempted to reestablish COMs during a critical stage of flight. Had I cross checked the flap indication with the handle position during the Landing Checklist we could have immediately remedied the situation.


Second narrative: [Report narrative contained no additional information.]


Synopsis: EMB-175 flight crew reported that while dealing with communication issues they neglected to complete the landing checklist and received an aural alert 'TOO LOW; FLAPS'.