A B737NG crew on approach to atl reported communication issues and confusion with ATC inquires.

Narrative:

On the dirty 3 arrival; passing haary; approach asked how the turbulence was. When we said it was ok; ATC asked if we were deviating without advising ATC of a deviation. After we said no; we looked at our course map and advised we were on course. The phase of flight did not afford time to expand on the discrepancy because we were switched to another approach frequency. Our flight instruments showed no anomalies. Upon arrival into atlanta; while monitoring the prm tower frequency; monitoring frequency tower asked us our airspeed. Shortly before switching from approach to tower; approach told us to reduce to 180 until the FAF. So; we were in the process of slowing our airspeed when prm monitor frequency asked our airspeed. After I responded on prm frequency that we were reducing airspeed; ATC tower frequency asked us if we were on the main frequency. I replied 'yes; and also monitoring 132.55.'this is the fourth or fifth time I have had a radio check; confirm airspeed; and confirm altitude on the prm monitoring frequency. My understanding; and I might be wrong; of the prm frequency is that it is for traffic alert and notice of deviations of an urgent and safety nature. We already diverted before this; so this just added to our complex day. My suggestion is to communicate on prm frequency for immediate safety concerns. I don't understand why main tower frequency doesn't communicate such concerns.

Original NASA ASRS Text

Title: A B737NG crew on approach to ATL reported communication issues and confusion with ATC inquires.

Narrative: On the DIRTY 3 Arrival; passing HAARY; Approach asked how the turbulence was. When we said it was ok; ATC asked if we were deviating without advising ATC of a deviation. After we said no; we looked at our course map and advised we were on course. The phase of flight did not afford time to expand on the discrepancy because we were switched to another Approach frequency. Our flight instruments showed no anomalies. Upon arrival into Atlanta; while monitoring the PRM Tower frequency; monitoring frequency Tower asked us our airspeed. Shortly before switching from Approach to Tower; Approach told us to reduce to 180 until the FAF. So; we were in the process of slowing our airspeed when PRM monitor frequency asked our airspeed. After I responded on PRM frequency that we were reducing airspeed; ATC Tower frequency asked us if we were on the main frequency. I replied 'Yes; and also monitoring 132.55.'This is the fourth or fifth time I have had a radio check; confirm airspeed; and confirm altitude on the PRM monitoring frequency. My understanding; and I might be wrong; of the PRM frequency is that it is for traffic alert and notice of deviations of an urgent and safety nature. We already diverted before this; so this just added to our complex day. My suggestion is to communicate on PRM frequency for immediate safety concerns. I don't understand why Main Tower frequency doesn't communicate such concerns.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1367467
Time
Date	201606
Local Time Of Day	1201-1800
Place
Locale Reference	ATL.Airport
State Reference	GA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737 Next Generation Undifferentiated
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 214
Person 2
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 244
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy