Bochsa Etude 7 from vingt etudes

[Elizabeth Volpé Bligh]

Do you mean dampened or muffled sounds? A dampening symbol under a chord refers only to that spot, unless there is a line indicating that the dampening is to continue. I don’t have this piece in front of me, but if you could scan the page and sent it in an email, I wouldn’t mind looking at it to answer your question.
Dots above the notes mean staccato for most instruments, but sometimes in harp music they can mean a light, staccato feel instead, if it is impossible to muffle after every note.