You may have noticed, that the well-known WSJT program displays the signal level above the noise in decibels. It's an interesting decibel game… But what in normal operation (CW/SSB)? The accuracy of S-meters tends to be very poor, but in case, that you will be asked to compare signals by the other station, who is doing some experiment, you have a very accurate measuring device at your disposal.
And human hearing. The following table shows, for example, replacing a coaxial cable with a less lossy one will result, increase performance and the like. It's a little different with antennas, the result is influenced by several factors of the antenna itself.
|Increment in dB||It seems like|
|1 ž 3||just a perceptible increase in signal strength|
|3||easily perceptible increase in signal strength|
|6||doubling the sound level|
|10||significant increase in signal strength|