Toward a comprehensive vowel space for whispered speech

Whispered speech, as a means of communication, has received prior research efforts on different aspects including some rough estimations/studies on the main vowels /ı,ε,æ,Λ,υ/. Despite these efforts, it still lacks a classic vowel space determination similar to the vowel acoustic measurements for normal speech which have played a central role in the development and testing of speech recognition and processing theories over the past few decades. The purpose of this study is to redress the shortfall through a preliminary vowel formant space for whispered speech, while comparing the results with corresponding phonated samples. Since the study was conducted using speakers from Birmingham, the analysis also briefly considers the possible effect of British West Midlands (WM) accent in comparison with Standard English (RP) accent. Thus, the paper presents the analysis of formant data showing differences between normal and whispered speech while also considering accentual effect on whispered speech.