An apparatus includes a frequency generator to generate an electrical signal. The apparatus also includes an acoustic transducer operably coupled to the frequency generator. The acoustic transducer converts the electrical signal into a first acoustic signal. The apparatus also includes an applicator operably coupled to the acoustic transducer. The applicator includes an acoustic generator to generate a second acoustic signal based on the first acoustic signal. The applicator also includes an applicator interface configured to apply the second acoustic signal to a patient.