Directivity of musical instruments have been studied for a long time. In the last decades, there has been a growing interest in imaging methods for the characterization and localization of sound sources. These developments are of great help to study the stationary and transient radiation behaviour of woodwind instruments. The time-domain Near-Field Acoustic Holography is one of these powerful imaging methods. NAH allows to separate the sources contributions from the different parts of an instrument. One of the advantage of the time-domain holography is to observe acoustic phenomena during transitory states. Most studies on recorder acoustic radiation were conducted during steady state, yet none of them focus on the attack transients. In order to investigate the acoustic radiation of the sopranino recorder, we use a semi-cylindrical microphone array, thus taking advantage of the geometrical symmetry of the recorder. In this study, the imaging method is used for the localization and the characterization of radiating sources on a sopranino recorder played by a performer. The array consists in a 4 angular and 11 longitudinal microphone arrangement. Taking into account the symmetry, the number of measurements points is 2 × 11 × 4 = 88. The recorder is located at the center of the cylindrical array. This study aims at highlighting an acoustic coupling between finger holes, labium and bell during the attack transient. This experiment allows us to validate the experimental protocol: semi-cylindrical array and time domain acoustic holography method for woodwind instruments radiation investigations.