ExtensionBeamform into a Higher Order Ambisonic signal (HOA), with near-field effect (NFE).
| in | 
 The input signal.  | 
| theta | 
 Azimuth, in radians.  | 
| phi | 
 Elevation, in radians.  | 
| radius | 
 Radius, in meters.  | 
| beamShape | 
 Keyword argument for beam shape. See discussion below.  | 
| order | 
 Ambisonic order.  | 
Three standard beam shapes are offered:
| keyword | beam shape | localisation vector | virtual microphone | 
\basic | strict soundfield | maximum velocity rV | Hyper-cardioid | 
\energy | energy optimised | maximum energy rE | Super-cardioid | 
\controlled | controlled opposites | minimum diametric energy | Cardioid |