Interesting question. Though superficially similar, those words actually sound different in all dialects. First of all, there is a long vowel at the end of ‘comhrá’ which is why the two cannot quite overlap. Because of this, in Munster Irish the stress moves to the last syllable. In Ulster Irish, the difference between long and short vowels is less marked, but in ‘comhartha’ you would still hear the ‘th’ which is absent in ‘comhrá’. Perhaps in Cois Fhairrge, the ‘th’ would disappear, but the ‘o’ would sound rather like ‘u’, plus there is still a long vowel at the end of ‘comhrá’. But yes, better listen to it on Teanglann, as Aled points out. 😀