Presentation to ASA St. Louis Chapter

On March 6, 2018 Mike Biffignani, President of Sondare Acoustics and President of the St. Louis Chapter of the Acoustic Society, presented to members of the chapter a summary of Human Echolocation. Included in the presentation were highlights from his meeting with Daniel Kish and a demonstration of the Sondare Echolocation Sound Beam. The meeting was attended by 13 acoustic and audio engineering professionals in the St Louis area including three members of the AES local chapter and a representative of the St Louis Society for the Blind.

The discussion included the importance and characteristics of the source signal and the echo and the processing of acoustic information by the brain. We also discussed the unique use of Human Echolocation by Daniel Kish using an oral tongue click as his source signal. We also discussed the use and characteristics of a wooden castanet as a source signal and how it’s frequency spectrum compares to an oral click.

We then discussed the technical aspects of a parametric array, sound beam, and how it might be useful for human echolocation. A demonstration of the Sondare Echolocation SoundBeam prototype was conducted. Several source signals were generated as a beam of sound and reflected off the walls of the room and compared to similar spherically spreading signals generated by a loudspeaker and by a wooden castanet. The group had a very informative discussion about what was heard, differences of the signals and echoes, usefulness of the sound beam and suggestions about how it could be used and improved for human echolocation. The diverse experiences and backgrounds of chapter members provided for a very enjoyable, enlightening discussion and chapter meeting.