You need to provide a reference to "Hale (1954)": it is virtually a certainty that the year is wrong, since this would have been an entirely different issue in 1954. There is, however, Morris Halle, who has written many things on the topic. The idea of having unified phonetics and phonology is, in fact, the theoretical starting point of pre-generative phonology Praguian and became a fundamental assumption of generative phonology as represented by Chomsky & Halle 1968, Postal 1968. We can contrast Ohala's view with that of Chomsky & Halle. Both deny that there are separate components of grammar: actually, it is most probable that Ohala does not have a concept of "grammar", in the sense that generative linguistics uses it.
The C&H view is that all language-specific sound rules are implemented by a set of phonological rules, which operate on a universal set of features that can have integer coefficients (though which on can say that a stop in French is "more voiced" that a stop in Swahili). These rules produce a set of instructions to the articulators, and the production of physical sound procedes thereafter in a non-linguistic way. That is, languages do not differ in how nasality is produced in [ana], once the specific integer values of these phonemes are set by rule.
Ohala on the other hand does not accomodate sound-system processes that aren't part of what have been called "postlexical phonology", thus there are no phonological rules of palatalization in Polish, there is no vowel alternation within the root in "dream ~ dreamt", Classical Arabic does not have rules deleting intervocalic glides. It is entirely unclear what his theory of language production is, since it appears that he holds that speakers have learned all of the words of their language and do not generate them from parts.
The basic dichotomy between Ohala and Chomsky & Halle is that for Ohala, everything is historical change, and for Chomsky & Halle, everything is synchronic grammar.