Research described in a previous paper [1] demonstrated that high accuracy of recognition of degraded speech is possible to achieve with an IMELDA acoustic representation. The present paper extends these findings and reports on new, incremental improvements to the recognition system. An IMELDA transform is derived for each individual user and it preserves the most salient acoustic features, simultaneously minimising the effects of signal degradation. Increasing recognition accuracy to 99% on speech recorded in a helicopter for the tested population of speakers has been possible through the introduction of a new method of deriving a noise threshold and a modified computation of an IMELDA transform. Problems pertinent to the integration of a prototype recogniser into a helicopter, and preliminary results of in-flight recognition tests are described. Finally, a short section deals with issues involved in computing a transform on a personal computer.