Influences of pellet markers on speech production behavior: Acoustical andperceptual measures

Peri- and intraoral devices are often used to obtain measurements concernin g articulator motions and placements. Surprisingly, there are few formal ev aluations of the potential influence of these devices on speech production behavior. In particular, the potential effects of lingual pellets or coils used in x-ray or electromagnetic studies of tongue motion have never been e valuated formally, even though a large x-ray database exists and electromag netic systems are commercially available. The x-ray microbeam database [Wes tbury, J. "X-ray Microbeam Speech Production Database User's Handbook, vers ion 1" (1994)] includes several utterances produced with pellets-off and -o n, which allowed us to evaluate effects of pellets for the utterance, She h ad your dark suit in greasy wash water all year, using acoustic and percept ual measures. Overall, there were no acoustic or perceptual measures that s howed consistent effects of pellets across speakers, but certain effects we re consistent either within a given speaker or in direction across a subgro up of the speakers. The results are discussed in terms of the general goodn ess of the assumption that point parameterization of lingual motion does no t interfere with normal articulatory behaviors. A brief screening procedure is suggested to protect articulatory kinematic experiments from those indi viduals who may show consistent effects of having devices placed on periora l structures. (C) 1999 Acoustical Society of America. [S0001-4966(99)04005- 9].