Related Experiment Video
Updated: Jul 8, 2026
09:23
A Low Cost Setup for Behavioral Audiometry in Rodents
Published on: October 16, 2012
Estimating bottlenose dolphin (Tursiops truncatus) hearing thresholds from single and multiple simultaneous auditory
James J Finneran1, Dorian S Houser, Dave Blasko
1U.S. Navy Marine Mammal Program, Space and Naval Warfare Systems Center, San Diego, Code 71510, 53560 Hull Street, San Diego, California 92152, USA. james.finneran@navy.mil
The Journal of the Acoustical Society of America
|January 8, 2008
Summary
This study assessed bottlenose dolphin hearing using auditory evoked responses. Simultaneous sound stimuli significantly reduced hearing test times while maintaining accuracy.
Area of Science:
- Marine Mammal Auditory Physiology
- Bioacoustics
- Cetacean Neurosensory Research
Background:
- Understanding bottlenose dolphin hearing is crucial for conservation and managing anthropogenic noise impacts.
- Previous hearing threshold estimations in dolphins were time-intensive, limiting practical application.
Purpose of the Study:
- To evaluate the efficacy of using simultaneous amplitude-modulated tones for rapid hearing threshold estimation in bottlenose dolphins.
- To compare the accuracy and time efficiency of single versus multiple simultaneous stimuli for auditory evoked response audiometry.
Main Methods:
- Auditory evoked responses were measured in four bottlenose dolphins (4-22 years old) using a jawphone transducer in air.
- Stimuli included single and multiple (4, 5, 9) sinusoidal amplitude-modulated tones across carrier frequencies from 10 to 160 kHz.
- Evoked potentials were recorded noninvasively, and responses were assessed using magnitude-squared coherence analysis.
Main Results:
- All dolphins demonstrated U-shaped audiograms with upper hearing cutoff frequencies exceeding 113 kHz.
- Estimating hearing thresholds using nine simultaneous stimuli reduced testing time to 5-9 minutes, compared to 23-37 minutes for single stimuli.
- Thresholds derived from single and multiple simultaneous stimuli showed good agreement.
Conclusions:
- Simultaneous amplitude-modulated tones provide a time-efficient method for assessing bottlenose dolphin hearing thresholds.
- This technique can be valuable for rapid hearing assessments in clinical or research settings.
- The findings support the use of multi-tone stimuli for practical audiometry in dolphins.
