Dull ache

[aleCcowaN]

Just to confirm

dull ache = dolor sordo ?

[poli]

Yes. That is a direct translation.

[chileno]

Yes, as in "muffled" (obsolete now in English for deaf)

[JPablo]

Both Oxford Superlex and Cambridge Klett bilingual use "sordo" as well, referring to an "ache".

Moliner gives,
D. sordo [o latente]. Dolor poco intenso, pero continuo y duradero.
And DRAE concurs with Moliner, (it also gives "dolor latente" = "dolor sordo")
~ sordo. 1. m. dolor que no es agudo, pero molesta sin interrupción.