In today's world of crystal clear radio reception of cellular, local FM broadcasting stations and short range handheld Communications very often there's nothing except the voice coming out of the speaker and it's just like they are sitting next to us. However as we move into the "doing phase" of "playing with" and using ALL of our gear we should understand that it's not always going to be a perfect signal.
Static will be inserted due to range or obstructions. Mobile users may have a picket fence effect as the station is moving past trees or utility poles. Signals may fade in and out as you go under a bridge.
Everyone is familiar with the in close "comm check" prior to deploying on a mission, even going to the store could be a "mission". The standard is "Lima Charlie" for loud and clear. But once you're at the store what if it's NOT loud and clear??
Knowing what your signal sounds like let's you know if you may need to enunciate your words more, possibly use phonetics to get the message through. That's where the RST report comes in.
R)eadability are you hearing all or only part of what I have said? The scale is 1-5, 1 being I know there's A signal but not understanding anything you said to 5 being I understood everything you said.
S)trangth: most radios have a signal strength meter of some sort. This is a scale of 1-9. Cellular phones use 4 bars, handhelds may use 5 etcetera. An strangth of 9 is perfect. 5 has a lot of static and 1 is just above the noise (very weak).
T)one: normally intented for Morse code tone it can be adapted to voice, sometimes a radio may be slightly off frequency making the voice sound unnatural. Some microphones may have issues, making it sound like you're talking into an empty coffee can. Scale is also 1-9 On voice, 1 being alien race is talking to you and 9 being a completely natural sounding voice.
So in practice, your mission, is to patrol your sector. Before you leave, fire up the comms units and with your comm guy/gal everyone checks in. "Net this is Alpha 1 comm check? Over" "Alpha 1 Lima Charlie out" Lima Charlie all around good to go.
15 minutes later you arrive at the furthest distance from camp.
"Net this is ...pha one sig..al re..ort over?" This is NOT a Lima Charlie signal, it's not even a 5 by nine report. At best this is a 35(9) report. Readable but with difficulty, there's likely weakening of the signal but the voice is still natural sounding. The net should make accurate reports. "Alpha 1 359, 359 over." Net must assume its own signal sounds the same to alpha 1 and repeats the report. "Net Roger standby"
"Net standing by" 2 minutes later as alpha 1 climbs to higher ground or away from trees... "Net this is Alpha 1 signal report over" "alpha 1 499, welcome back over" "net Roger, all clear, my location 8365 3489 over"
"Alpha 1 net good copy return to base over."
"Net alpha 1 Wilco alpha 1 out"
Hope this may help you as you practice using your gear and in finding out the capability of your radio Communications gear.