Acoustic imaging in bat sonar: Echolocation signals and the evolution of echolocation

@article{Simmons2004AcousticII,
  title={Acoustic imaging in bat sonar: Echolocation signals and the evolution of echolocation},
  author={James A. Simmons and R. A. Stein},
  journal={Journal of comparative physiology},
  year={2004},
  volume={135},
  pages={61-84}
}
SummaryEcholocating bats behave as though they perceive the crosscorrelation functions between their sonar transmissions and echoes as images of targets, at least with respect to perception of target range, horizontal direction, and shape. These data imply that bats use a multi-dimensional acoustic imaging system for echolocation with broadband, usually frequencymodulated signals. The perceptual structure of the echolocation signals used by different species of bats was investigated using the… 

Accuracy of target ranging in echolocating bats: acoustic information processing

Summary1.Echolocating bats use the time delay between emitted sounds and returning echoes to determine the distance to an object. This study examined the accuracy of target ranging by bats and the

Auditory Mechanisms of Echolocation in Bats

Audio-motor circuits, within and across brain regions, lay the neural foundation for acoustic orientation by echolocation in bats, which supports 3D perception of objects in the surroundings and permits spatial navigation in complete darkness.

Development and application of an echolocation model inspired by bats

Overall, this study has shown that customised auditory processing of the echolocating signal improves the quality of sonar representation and the results of investigations using the head-related transfer function (HRTF) of the bat-head cast guide the future design of effective adaptive signals based on the range-dependent HRTFs, to potentially enhance the performance ofSonar systems.

Discrimination of jittered sonar echoes by the echolocating bat, Eptesicus fuscus: The shape of target images in echolocation

The locations of both 0° and 180° phase peaks in the performance curves shift along the time axis by an amount that matches neural amplitude-latency trading in Eptesicus, confirming a temporal basis for jitter discrimination.

Convergence of temporal and spectral information into acoustic images of complex sonar targets perceived by the echolocating bat, Eptesicus fuscus

Summary1.FM echolocating bats (Eptesicus fuscus) were trained to discriminate between a two-component complex target and a one-component simple target simulated by electronically-returned echoes in a

Ultrasound Production, Emission, and Reception

This chapter first discusses how sounds are produced by the bat larynx by outlining its characteristic morphological features and detailing general sound production mechanisms, including non-linear features that play a key role in enabling echolocating bats to switch between eCholocation and communication sounds.

Echo-intensity compensation in echolocating bats (Pipistrellus abramus) during flight measured by a telemetry microphone.

Findings provide direct evidence that bats adjust pulse intensity to compensate for changes in echo intensity to maintain a constant intensity of the echo returned from the approaching target at an optimal range.

Neural Processing of Naturalistic Echolocation Signals in Bats

This work reviews how does stimulus history affect neural processing, how spatial information from multiple objects and how echolocation signals embedded in a naturalistic, noisy environment are processed in the bat brain, and discusses the huge potential that state-of-the-art recording techniques provide.

Spatial perception and adaptive sonar behavior.

The results of this study show that the distance and the angular offset of the distracter influence sonar vocalization parameters of the big brown bat, Eptesicus fuscus, and the results hold implications for understanding spatial information processing and perception by echolocation.

Amplitude discrimination is predictably affected by echo frequency filtering in wideband echolocating bats

Bats’ performance was significantly poorer when the lower frequencies in echoes were attenuated, compared to higher frequencies, and their ability to distinguish between virtual targets at the same simulated range from echoes arriving at the the same delay indicates a high level of focused attention for perceptual isolation of one and suppression of the other.
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References

SHOWING 1-10 OF 58 REFERENCES

Perception of echo phase information in bat sonar.

Echolocating bats (Eptesicus fuscus) can detect changes as small as 500 nanoseconds in the arrival time of sonar echoes when these changes appear as jitter or alternations in arrival time from one

ECHOLOCATION WITH WIDE-BAND WAVEFORMS: BAT SONAR SIGNALS

Abstract : The wide-band, echolocating sonar signals of bats are investigated with reference to statistical estimation theory to ascertain the implications of this class of signals. The work is

Echolocation by free-tailed bats (Tadarida)

The differences observed in echolocation among many species and families of bats appear to be evolutionary adaptations to some of the same features of the acoustic environment to which Tadarida responds behaviorally.

Echolocation: discrimination of targets by the bat, Eptesicus fuscus.

The ability of the bat to discriminate between targets which produce echoes that arrive at theBat's ears overlapping each other for 90 to 100% of their total duration demonstrates the effectiveness of the mechanisms in the bat's sonar for rejecting interference caused by multiple-target clutter.

Neurophysiological studies on echolocation systems in awake bats producing CF-FM orientation sounds.

The bats Pteronotus parnellii, P. suapurensis and Noctilio leporinus emit orientation sounds first containing a constant-frequency (CF) and then a frequency-modulated (FM) component, which indicates that the FM is important to echolocation in all these bats and that the CF component is more essential to e cholocated species.

The resolution of target range by echolocating bats.

  • J. Simmons
  • Environmental Science
    The Journal of the Acoustical Society of America
  • 1973
Comparisons between discrimination performance and autocorrelation functions of echolocation sounds used in the discriminations suggest that these bats possess some neural equivalent of a matched‐filter, ideal sonar receiver which functionally cross‐correlates a replica of the outgoing signal with the returning echo to detect the echo and determine its arrival time.

Neural processing mechanisms in echolocating bats, correlated with differences in emitted sounds.

  • A. Grinnell
  • Physics
    The Journal of the Acoustical Society of America
  • 1973
Bats that emit pulses containing constant wavelength (CW) components preceding an FM sweep show neural adaptations that differ conspicuously from those of bats emitting purely FM pulses. In contrast

Dynamic properties of the compensation system for doppler shifts in the bat,Rhinolophus ferrumequinum

Summary1.Echolocation sounds of the batRhinolophus ferrumequinum were played back to the bat as artificial echoes shifted in frequency by a few kHz (0–4 kHz) without distortion of the amplitude and

Directional sensitivity of echolocation in the horseshoe bat,Rhinolophus ferrumequinum

The prominent downward side lobe of emission does not conspicuously increase echolocation effectiveness in the direction of the ground, since hearing sensitivity is falling off so steeply in that direction, but without this downward beam of emission, signals from below the bat would be that much less effective.

Target Structure and Echo Spectral Discrimination by Echolocating Bats

Bats may be capable of classifying targets from echo spectral signatures and might thus be able to distinguish among flying insect prey by sonar.
...