SPEECH LEVEL DISCREPANCY AROUND THE HEAD OF A TALKER - A NEW LOOK AT LAVALIER & HANDSET MICROPHONE PLACEMENT TECHNIQUES
IR Cushing, F.F. Li, Trevor J. Cox · 2023
Accurate speech signal acquisition is important in many applications and one important consideration is the best place to position near-field microphones.For precise speech intensity level and frequency analysis, discrepancies between speech signals recorded at different near-field microphones are of particular interest.The human voice has a complicated near-field patternsound propagation from the mouth is liable to be affected not just by diffraction and reflection effects of the environment but by the actual human body itself.Many different applications depend on the reliable transmission of speech through nearfield microphone positions, such as mobile phones, automatic speech recognition systems and television broadcasts.It is useful to compare such near-field measurements to that of a 1 metre reference microphone, as this is a typical speaker-listener distance in many conversational settings.This study aims to discover the level and frequency discrepancies between such microphone positions, in order to build compensation curves so that the level and frequency content of a 1m distance reference microphone can be matched to those measured on a microphone placed in the near-field.The result of these compensation curve filters will 'mimic' the speech signal as heard by a listener in a typical conversation.As previous work has shown, the acoustic-phonetic consequences of different near-field microphone positions 1 are often overlooked.This study will aim to take these discrepancies into account, using spectrographic analysis to look at some finestructures of speech and the implications that such microphone differences may have on speech intelligibility.