'wary voice' is correct and usable in written English.
You can use it when someone is speaking in a cautious or apprehensive manner. For example: She spoke in a wary voice, aware of how vulnerable she felt in the presence of the intimidating figure.
With a wary voice, Ms. Melroy radioed to the ground, "We, uh, detected some, what appears to be a wraparound or some damage".
It emphasises the friction between Jesus and his disciple Judas in the build-up to the betrayal, with the latter presented as a wary voice of dissent among Jesus's followers.
One of the few blank spaces in his crowded discography is the great salsa-inspired album that he didn't make: the one where the bright certainty of the horn section pulled against the wary voice of the guy on the cover, hemming and hawing about his place in the world.
And with Britain's departure, the EU will lose one of its loudest Putin-wary voices.
That's because Amanda Foreman's panel have been warier in voicing what guided them – no negative comments about rejected titles, no loose populist talk enthusing about quick reads and page-turners.
On the rare occasion I ran into a fellow enthusiast, we would speak in hushed voices, wary of public ridicule.
Even though they feel betrayed by Democrats who did not use their leverage on government funding to get Dreamer protections and wary of Republicans who voice support but don't act, undocumented youth will keep pushing lawmakers.
Yet after the humiliation of the Copenhagen climate talks, at which the EU barely had a voice, even countries wary of integration would like Europe to become smarter at diplomatic strategy, once it has a common position.
Her voice, usually so lively, sounded wary and defensive: "I just can't talk now.
Davies, though, is wary of being regarded as the musical voice of London.
Dr. Doddington hopes that whatever comes, future vendors of voice authentication systems will be wary of making facile comparisons to fingerprints, less they offer false assurances.
