Thx to guest ixltixl for his
post, I tried it and it works
IRQ=5 yeah baby
And I was sure that I uploaded the old version I had and there were sound effects on old Pentium. Now that I think of it, it was always strange why default SB setting for IRQ in DOSBox is 7, because in Serbia in times of Pentiums and 486s, we all used 5. I thought that is default, that only some games use 7 for whatever reason. Later when I got used to DOSBox, I start thinking that it doesn't really matter, but I'm glad to see 5 again, it does bring back some memories.
(Naturally I still have no clue what IRQ is, I guess it takes only one step - search it on the net, but I'll leave it this way for now)