The call station has a cardioid, supervised microphone on a gooseneck stem with good speech intelligibility. A limiter and a speech filter improve intelligibility and prevent clipping of the audio. It has a volume control for the monitoring speaker and the headset. When it plays a chime or a pre-recorded message, the call station activates its speaker. When a headset is connected, it replaces the microphone and speaker. The call station has its own DSP, and converts between analog and digital audio. The audio processing can include sensitivity adjustment, limiting, and parametric equalization.
Specifications
Electrical
External power supply : 18 to 56 VDC
Power consumption : 4.4 W (DC) excluding keypads
Microphone
Nominal acoustic input level : 75 to 90 dB SPL
S/N : >60 dB at 85 dB SPL
Frequency response : 340 Hz to 14 kHz (-3 dB)
Loudspeaker
S/N : 80 dB at max. output
Sound pressure level : 85 dB (SPL) at 0.5 m and 1 kHz
Headset
Connector : 3.5 mm jack
Recommended type : Hosiden HBH 0058