Morphological differences affect speech transmission over bone conduction.

Area of Science:

• Audiology
• Bioacoustics
• Craniofacial Anatomy

Background:

• Bone conduction (BC) bypasses the outer and middle ear, transmitting sound via skeletal vibrations.
• Individual variations in craniofacial morphology are known but their effect on BC sound transmission is understudied.
• Speech intelligibility is a key measure for assessing the quality of auditory signals.

Purpose of the Study:

• To investigate how individual craniofacial morphology affects bone-conducted speech intelligibility.
• To determine if skull shape influences the perception of bone-conducted sounds at different locations.
• To provide data for improving BC hearing technologies.

Main Methods:

• Collected anthropometric craniofacial measurements from 32 participants.
• Recorded speech using bone microphones on 8 diverse talkers at various skull positions.
• Assessed speech intelligibility using the Modified Rhyme Test with 24 diverse listeners using BC headphones.

Main Results:

• Skull morphology significantly influences bone conduction speech intelligibility.
• The effect of morphology on intelligibility varies depending on the skull location of the bone transducer.
• Individual differences in craniofacial structure demonstrably alter BC sound transmission.

Conclusions:

• Craniofacial morphology is a critical factor in bone conduction speech perception.
• Tailoring BC technology to individual skull shapes can optimize performance.
• Further research into morphological effects will advance BC hearing aid and communication device design.