A comparative study of narrowband vocoder algorithms in Air Force operational environments using the Diagnostic Rhyme Test
Abstract
This report presents a summary of work performed at Lincoln Laboratory aimed at improving the intelligibility of 2.4 kbps vocoders to be used in USAF operational environments. The distortions present in some of these environments, particularly the F-15 fighter aircraft, can place a severe burden on the speech modelling capabilities of contemporary vocoders. To study these effects and the benefits of various algorithmic improvements, the Diagnostic Rhyme Test was used as a means of providing an objective measure of relative system performance. A wide range of areas was explored through the use of real time computer simulations, including the effects of modified analysis and synthesis techniques, design parameter choices, interoperability, and environmental factors. The purpose of this report is to assemble and document the extensive body of DRT data which has been collected and thereby provide a means for the selection of design parameters likely to lead to improved vocoder performance.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- January 1982
- Bibcode:
- 1982STIN...8226546S
- Keywords:
-
- Aircraft Communication;
- Algorithms;
- Intelligibility;
- Vocoders;
- Computerized Simulation;
- Evaluation;
- F-15 Aircraft;
- Flight Conditions;
- Flight Simulation;
- Signal Processing;
- Communications and Radar