When I worked on a large historical sailing ship that required a dozen crew to perform tasks like raising sails, tacking, or reefing, we followed a call-and-response verbal command system for many of the same reasons.
When the helmsman would yell out "Ready about!", we would check the surroundings and respond "Ready!", then we would listen for "Helms Alee!" and prepare to switch sides and trim the sails. This process made sure that all of the crew were synchronized as to the current step in the process.[0]
When I used to do manual labour, I used to do this when told to do tasks. e.g. if someone said "Go and sweep the leaves and put them in the bin", I'd clarify and say "So I'm sweeping those leaves and putting them in the bin?".
It worked well in making sure everyone was on the same page about what I was actually supposed to be doing. I eventually stopped doing it though because people got annoyed and thought I was stupid or just not listening to them, which was ironic because that's exactly the opposite of what was happening.
It's a shame really, because it did minimise errors. There's nothing more annoying for everyone then when someone spends hours doing the wrong task because of poor communication.
What I do when I want a final confirmation that I understood right is say what I'll do instead of asking. In your example, it would be, "Ok, then I'll sweep those leaves and put them in the bin."
But, who knows, it might not have made a difference. In my case, my boss already knows that I like to be extra certain that we're both on the same page.
That's an important distinction. If you sound like you're questioning every instruction or you don't understand the tasks then your boss is going to get frustrated with you.
If you have a poor memory like me, repeating things back is important to help you remember them too. Since I work in office type environment, I try to repeat things back by writing them down where both the requester and I can see them - such as in a job ticket or email. This also helps if a third party joins the task later or if the task gets put on hold.
Whereas at the automotive shop I used to work at, everyone else picked that habit up from me. I'd picked it up from experience in aviation line service during high school. My coworkers acted annoyed for the first week, but they quickly realized I didn't expect a response and it made communication in a noisy shop clearer.
Especially after the day that a coworker got confused about which truck was which, and drilled a 3.5" hole in the bed of a brand new truck (thinking it was getting a gooseneck hitch). After that, everyone else started repeating verbal instructions as well.
I do this also at my office -- it massively helps avoid misunderstandings, errors due to miscommunication, and other screw-ups. Like Hamlet said -- 'we must speak by the card, or else equivocation will undo us!'
I totally agree that the method you are using is a good habit. I noticed that cashiers often call out the denominations of money I hand them for a purchase, which too helps. I used to deliver newspapers late at night and once lost count (while counting in my head) of how many heavy bundles that I had loaded from one truck to another, which required me to start over - and on a cold night too. Thereafter, I picked up the habit of counting aloud, especially if somebody else came by and distracted me.
Cashiers in Japan always count out loud both what they receive and what they give back.
Cashiers in my home country never do. And sometimes I forget what I handed over.. it would have been useful then to have the verbal confirmation. Not to mention the time in Mexico when a gas station employee tricked me.. oh well, maybe not, in the latter case.
Call backs! A really good practice. As having also worked on a historical ship the bit that always gets me is when working on helm when needing to communicate our heading we say "one five three" rather than "one hundred fifty three" and then that is repeated back.
Makes it much more difficult to make mistakes this way.
Same in aviation, the ICAO phonetic alphabet is meant to reduce uncertainty over historically poor radio communications. Plus readback to air traffic control and so on is relatively standardized to allow for a few chances to realize you got the wrong thing down.
"Steer zero nine zero", "Zero nine zero aye" is the right way of doing a callback compared to "Ready about!", "Ready!" Repeating the information back, instead of just saying "yes" ensures that the correct message has been received.
My experience with this was relaying a message between the driver and guard, to reverse a train on a main railway line. The guard answered "yes" and there was hell to pay as the train reversed across a section boundary. The "yes" response ensured the guard received a message, but not that he received the correct message.
You are correct. For many commands such as raising sails we would repeat the command across the deck. My recollection was that distinct responses were reserved for potentially dangerous maneuvers where the helm needed to make sure the crew was performing the correct step at the correct time.
It seems silly until you have to do it in a storm, with wing literally howling into your ears. Combinations of sounds, gestures and readbacks are used anywhere loud noises are to be expected. Pretty much everything in aviation and the military requires some such layering.
The same call-and-response style is the standard for modern sailboats even if they can be single-handed in operation, because if somebody's out of place during a tack the boom can sweep them right off the boat when it goes from one side to the other.
As most modern sailboats are much smaller than a "Tall Ship" it is also a lot of fun to switch from port to starboard while the ship is coming about ... hopefully before the boom starts to swing.
In racing dinghies when tacking you often don't actually change sides until the boom has come across. Then when you do cross you are returning the boat to upright from nearly capsized. That drags the sail through the air creating a local increase in effective wind-speed, helping to re-accelerate after the speed lost during the tack.
One local burger joint made it a habit to not only call out your order to the crew in the kitchen, but that the kitchen would sing out the order back, with playful names for each type of thing on the menu.
Seemed to keep spirits up and probably had the side-effect of reducing errors.
When the helmsman would yell out "Ready about!", we would check the surroundings and respond "Ready!", then we would listen for "Helms Alee!" and prepare to switch sides and trim the sails. This process made sure that all of the crew were synchronized as to the current step in the process.[0]
[0] http://lrsailingcenter.com/posts/tacking/