A telecommunication device for the deaf shall be purchased by the vocational rehabilitation division of the department of education and installed in the office of the municipal police department of any municipality with a population in excess of ten thousand inhabitants if the division determines and verifies that at least five telecommunication devices for the deaf are in use by deaf persons in the municipality, and in the office of the county sheriff in counties not having a municipality with a population in excess of ten thousand inhabitants if the division determines and verifies that at least five such devices are in use by deaf persons in that county.