Noise at the point of connection of the copy paste of a sound

Hi everyone.
I have two recordings of the same song sung by a tenor. The recordings are almost identical. I decided to use the number 1. However, there is a note that I would like to replace with the recording number 2, because it seems to be of better quality. But when I copy and paste to replace it, I hear a noise (like click or tuc). In the spectrum I see a red bar upwards. I made several attempts and moves, but nothing to do, the noise is always there. What can I do to avoid it? Thanks to those who want to help me.

P.S. I have Audacity 2.2.2 and Windows 10.

Ciao a tutti.
Ho due registrazioni dello stesso brano cantate da un tenore. Le registrazioni sono state eseguite una dopo l’altra e sono quasi identiche. Ho deciso di usare la numero 1. C’è però una nota che vorrei sostituire con quella della registrazione numero 2, perché mi sembra di migliore qualità. Ma nel momento in cui faccio copia-incolla per sostituirla, si sente un rumore (tipo click o tuc). Nello spettro visualizzo una barra rossa verso l’alto. Ho fatto diversi tentativi e spostamenti, ma niente da fare, il rumore c’è sempre. Che posso fare per evitarlo? Grazie a chi mi vorrà dare un aiuto.

P.S. Ho Audacity 2.2.2 e Windows 10.

Try joining the files with a short crossfade. (Fade-out, fade-in, and overlap.) Something like 100 milliseconds or less should give you a smooth splice without sounding like a crossfade.

It’s either [u]DC offset[/u] or you didn’t cut at the [u]zero crossings[/u], but either way a crossfade should give you a smooth transition.

Thank you so much.
I’ve never used a crossfade, I’m experimenting a little to figure out how to do it. I hope to resolve. However, I should have understood what the real problem is