In the spatial acoustic signal processing

for the issue of dimensionality mismatch between 2-dimensional (2D) sound field synthesis and practical sound source

and the issue of near-field distortion in the near-field sound source synthesis

this paper presents a 2.5-dimensional (2.5D) sound field synthesis method and a modified Wiener filter method for near-field compensation.The 2.5D sound field synthesis is achieved using the spherical harmonics expansion of higher order ambisonics (HOA).The modified Wiener filter is used to compensate the near-field distortion which arises when HOA is utilized to reproduce a 2.5D near-field sound source.Based on the concept of continuous loudspeaker array hypothesis

a general expression of the loudspeaker driving signal is derived.The experiments show that the proposed method reduced the relative error of the synthesized 2.5D near-field from 0.23 to 0.031 in comparison with the cosine regularization method.Meanwhile

the proposed method provides a larger effective listening area compared with the high-pass filter method.