A Comprehensive Vowel Space for Whispered Speech

Whispered speech is a relatively common form of communications, used pri-marily to selectively exclude or include potential listeners from hearing a spo-ken message. Despite the everyday nature of whispering, and its undoubted usefulness in vocal communications, whispers have received relatively little research effort to date, apart from some studies analysing the main whispered vowels and some quite general estimations of whispered speech characteris-tics. In particular, a classic vowel space determination has been lacking for whispers. For voiced speech, this type of information has played an im-portant role in the development and testing of recognition and processing theories over the past few decades, and can be expected to be equally useful for whisper-mode communications and recognition systems. This paper aims to redress the shortfall by presenting a vowel formant space for whispered speech, and comparing the results with corresponding phonated samples. In addition, since the study was conducted using speakers from Birmingham, the analysis extends to discuss the effect of the common British West Midlands (WM) accent in comparison with Standard English (RP). Thus, the paper presents the analysis of formant data showing dif-ferences between normal and whispered speech while also considering an accentual effect on whispered speech. Keywords