An assembly of a sound generator having a sound output, a spout connected to the receiver, the spout having a sound channel having a first opening connected to the sound output and a second opening from which sound may be output. The spout has one or more third openings blocked by fastening portions of a dome, and a sensor positioned in the sound channel at the third opening(s). Sound may pass the sensor in the sound channel while travelling in the third opening(s). The assembly may be a personal hearing instrument and the sensor may be a microphone.