  Acoustic velocity vectors are important for human's localization of sound at
low frequencies. This paper proposes a sound field reproduction algorithm,
which matches the acoustic velocity vectors in a circular listening area. In
previous work, acoustic velocity vectors are matched either at sweet spots or
on the boundary of the listening area. Sweet spots restrict listener's
movement, whereas measuring the acoustic velocity vectors on the boundary
requires complicated measurement setup. This paper proposes the cylindrical
harmonic coefficients of the acoustic velocity vectors in a circular area (CHV
coefficients), which are calculated from the cylindrical harmonic coefficients
of the global pressure (global CHP coefficients) by using the sound field
translation formula. The global CHP coefficients can be measured by a circular
microphone array, which can be bought off-the-shelf. By matching the CHV
coefficients, the acoustic velocity vectors are reproduced throughout the
listening area. Hence, listener's movements are allowed. Simulations show that
at low frequency, where the acoustic velocity vectors are the dominant factor
for localization, the proposed reproduction method based on the CHV
coefficients results in higher accuracy in reproduced acoustic velocity vectors
when compared with traditional method based on the global CHP coefficients.
