I think it is "fibre-only [g]rounds/grinds"
not so sure about the "grounds though, and the sentence doesn't make a lot of sense.
Is there a longer extract somewhere else?
Normally I have no problem understanding British English by reasonably clear-spoken native speakers. This is tricky because it's such a specialised field.
Is this work, are you able to say why you are having to do these strange transcriptions?
Oh and the bit in the earlier transcript that is still unclear,
"the shoulder, not like the _______* we used to use before......"
*Antonathe or Anton8 or Antoinette (bad English pronounciation of this French name).
I don't think it's "alternate". The sound of the A in the beginning of alternate, in British pronounciation, is completely different from the word here.