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The Alpha System


The main parts of the Alpha Interface System (AIS) are illustrated above. The model shown is the development model, leading eventually to the Mk 4 (Lynx) and Mk5 models which may incorporate features of the above.




The operator contacts both hand-plates, left and right - and the resultant signal is picked up by the inductive loop, (L-loop), which is in turn connected to the radio (or synchronous detector in another option). The acoustic output is picked up by two sound-meters/microphones and recorded. On playback the tape is selectively re-recorded into the PC where proprietary waveform analysis and conditioning software is applied.



Performance Specification

(Development Model)


Number of recognisable utterances /180 secs. operation.

Number of utterances at or above 50% intelligibility/180 secs *

Number of utterances at or above 75% intelligibility/180 secs *

* Figures marked thus are best estimates and are subject to correction by the results of listening panels.

Min. Avg. Max.

3 6 15

2 5 8

0 0.5 2