Intelligibility of ICAO (International Civil Aviation Organization) Spelling Alphabet Words and Digits Using Severely Degraded Speech Communication Systems. Part 1. Narrowband Digital Speech.
Abstract
The Diagnostic Rhyme Test (DRT) is widely used to evaluate digital voice systems. Would-be users often have no reference frame of interpreting DRT scores in terms of performance measures that they can understand, e.g., how many operational words are correctly understood. This research was aimed at providing a better understanding of the effects of very poor quality speech on human communication performance. It is especially important to determine how successful communications are likely to be when the speech quality is severely degraded. This report compares the recognition of ICAO spelling alphabet words (ALFA, BRAVO, CHARLIE, etc) with DRT scores for the same conditions. Confusions among the spelling alphabet words are also given. Two types of speech degradation were selected for investigation: narrowband digital speech (the DoD standard linear predictive coding algorithm operating at 2400 bits/s) with varying bit-error rates and analog jamming. The report will be in two parts. Part 1 covers the narrowband digital speech research, and Part 2 will cover the analog speech research.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 31, 1987
- Accession Number
- ADA179849
Entities
People
- Astrid Schmidt-nielsen
Organizations
- United States Naval Research Laboratory