James J Finneran

United States Navy, Monterey, California, United States

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Publications (183)273.12 Total impact


  • No preview · Conference Paper · Dec 2015

  • No preview · Conference Paper · Dec 2015
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    ABSTRACT: Auditory thresholds were measured in three bottlenose dolphins before and after exposure to ten impulses from a seismic air gun. Thresholds were measured using behavioral and electrophysiological methods to determine the amount of temporary threshold shift induced. The results suggest that the potential for seismic surveys using air guns to cause auditory effects on dolphins may be lower than previously predicted; however, two of the three dolphins exhibited "anticipatory" behavioral changes at the highest exposure condition that suggested they were attempting to mitigate the effects of the exposures.
    No preview · Article · Nov 2015 · Advances in Experimental Medicine and Biology
  • Jason Mulsow · James J Finneran
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    ABSTRACT: A California sea lion performed a psychophysical auditory discrimination task with a set of six stimuli: three barks recorded from conspecific males and high-pass filtered versions of the barks that removed the majority of energy at fundamental frequencies. Discrimination performance and subject reaction times (RTs) suggested that the vocalizations were all perceived as fairly dissimilar. This preliminary study hints that low-frequency components are a salient part of the California sea lion bark despite elevation of this species' aerial hearing thresholds and the potential for elevated environmental noise levels at frequencies below 1 kHz.
    No preview · Article · Nov 2015 · Advances in Experimental Medicine and Biology
  • James J Finneran · Jason Mulsow · Carolyn E Schlundt
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    ABSTRACT: Subjective loudness measurements are used to create equal-loudness contours and auditory weighting functions for human noise-mitigation criteria; however, comparable direct measurements of subjective loudness with animal subjects are difficult to conduct. In this study, simple reaction time to pure tones was measured as a proxy for subjective loudness in a Tursiops truncatus and Zalophus californianus. Contours fit to equal reaction-time curves were then used to estimate the shapes of auditory weighting functions.
    No preview · Article · Nov 2015 · Advances in Experimental Medicine and Biology
  • Dorian S Houser · Steven W Martin · James J Finneran
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    ABSTRACT: Acoustic dose-response functions have been recommended as a means of predicting behavioral impacts on marine mammals from anthropogenic noise exposure. Thirty bottlenose dolphins and fifteen sea lions participated in a controlled exposure study to explore dose-response relationships to the received level of a simulated sonar signal. Both species showed an increase in the probability of response and in the severity of response with increased received levels. Differences in species sensitivity were noted in habituation and the impact of age on responsiveness.
    No preview · Article · Nov 2015 · Advances in Experimental Medicine and Biology
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    ABSTRACT: Odontocete cetaceans are acoustic specialists that depend on sound to hunt, forage, navigate, detect predators, and communicate. Auditory masking from natural and anthropogenic sound sources may adversely affect these fitness-related capabilities. The ability to detect a tone in a broad range of natural, anthropogenic, and synthesized noise was tested with bottlenose dolphins using a psychophysical, band-widening procedure. Diverging masking patterns were found for noise bandwidths greater than the width of an auditory filter. Despite different noise types having equal-pressure spectral-density levels (95 dB re 1 μPa(2)/Hz), masked detection threshold differences were as large as 22 dB. Consecutive experiments indicated that noise types with increased levels of amplitude modulation resulted in comodulation masking release due to within-channel and across-channel auditory mechanisms. The degree to which noise types were comodulated (comodulation index) was assessed by calculating the magnitude-squared coherence between the temporal envelope from an auditory filter centered on the signal and temporal envelopes from flanking filters. Statistical models indicate that masked thresholds in a variety of noise types, at a variety of levels, can be explained with metrics related to the comodulation index in addition to the pressure spectral-density level of noise. This study suggests that predicting auditory masking from ocean noise sources depends on both spectral and temporal properties of the noise.
    No preview · Article · Nov 2015 · Advances in Experimental Medicine and Biology
  • Jason Mulsow · Carolyn E. Schlundt · Lacey Brandt · James J. Finneran
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    ABSTRACT: Loudness perception by non-human animals is difficult to study directly. Previous research efforts have instead focused on estimating loudness perception using simple reaction time (RT) data. These data are used to generate equal latency contours that serve as a proxy for equal loudness contours. To aid the design of auditory weighting functions for marine mammals, equal latency contours were generated using RT data for two marine mammal species that are representative of broader functional hearing groups: the bottlenose dolphin (under water) and California sea lion (in air). In all cases, median RT decreased with increasing tone sound pressure level (SPL). The equal latency contours corresponding to near-threshold SPLs were similar to audiograms for both species. The sea lion contours showed some compression at frequencies below 1 kHz; however, a similar pattern was not apparent in the more variable data for dolphins. Equal latency contours for SPLs greater than approximately 40 dB above threshold diverged from predicted equal loudness contours, likely due to the asymptotic nature of RT at the highest tested SPLs. The results suggest that auditory threshold data, potentially augmented with compression at low frequencies, may provide a useful way forward when designing auditory weighting functions for marine mammals.
    No preview · Article · Nov 2015 · The Journal of the Acoustical Society of America
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    James J. Finneran
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    ABSTRACT: One of the most widely recognized effects of intense noise exposure is a noise-induced threshold shift - an elevation of hearing thresholds following cessation of the noise. Over the past twenty years, as concerns over the potential effects of human-generated noise on marine mammals have increased, a number of studies have been conducted to investigate noise-induced threshold shift phenomena in marine mammals. The experiments have focused on measuring temporary threshold shift (TTS) - a noise-induced threshold shift that fully recovers over time - in marine mammals exposed to intense tones, band-limited noise, and underwater impulses with various sound pressure levels, frequencies, durations, and temporal patterns. In this review, the methods employed by the groups conducting marine mammal TTS experiments are described and the relationships between the experimental conditions, the noise exposure parameters, and the observed TTS are summarized. An attempt has been made to synthesize the major findings across experiments to provide the current state of knowledge for the effects of noise on marine mammal hearing.
    Preview · Article · Sep 2015 · The Journal of the Acoustical Society of America

  • No preview · Conference Paper · May 2015
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    ABSTRACT: To investigate the auditory effects of multiple underwater impulses, hearing thresholds were measured in three bottlenose dolphins before and after exposure to 10 impulses produced by a seismic air gun. Thresholds were measured at multiple frequencies using both psychophysical and electrophysiological (auditory evoked potential) methods. Exposures began at relatively low levels and gradually increased over a period of several months. The highest exposures featured peak sound pressure levels from 196 to 210 dB re 1 μPa, peak-peak sound pressure levels of 200-212 dB re 1 μPa, and cumulative (unweighted) sound exposure levels from 193 to 195 dB re 1 μPa(2)s. At the cessation of the study, no significant increases were observed in psychophysical thresholds; however, a small (9 dB) shift in mean auditory evoked potential thresholds, accompanied by a suppression of the evoked potential amplitude function, was seen in one subject at 8 kHz. At the highest exposure condition, two of the dolphins also exhibited behavioral reactions indicating that they were capable of anticipating and potentially mitigating the effects of impulsive sounds presented at fixed time intervals.
    No preview · Article · Apr 2015 · The Journal of the Acoustical Society of America
  • James J. Finneran · Jason Mulsow · Dorian S. Houser · Robert F. Burkard
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    ABSTRACT: Auditory evoked potential measurements are commonly used for hearing assessment in marine mammals for which psychophysical testing is not practical. Evoked potential measurements typically employ electrical signals consisting of short-duration tone-pips or sinusoidal amplitude modulated tones, which are then presented to piezoelectric underwater sound projectors. Although tone-pip and short-duration tonal stimuli may possess relatively narrow frequency bandwidth, the resulting physiological responses may possess much greater bandwidth, especially for lower frequency stimuli at higher stimulus levels. In this study, high-pass masking noise techniques were used to examine the place specificity of auditory evoked responses from click, tone-pip, and sinusoidal amplitude modulated tones in bottlenose dolphins (Tursiops truncatus). The experimental methods for generating and spectrally equalizing masking noise and click stimuli will be presented, along with the effect of compensated clicks with uncompensated clicks and ABR latencies and amplitudes. [Funded by U.S. Navy Living Marine Resources Program.]
    No preview · Article · Apr 2015 · The Journal of the Acoustical Society of America
  • Jason Mulsow · James J. Finneran · Carolyn E. Schlundt
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    ABSTRACT: Reaction time (RT) data obtained from simple tonal detection tasks have been used to estimate frequency-specific equal-loudness contours in non-human animals. In order to guide the design of auditory weighting functions for marine mammals, equal-latency contours were generated using RT data from a simple tonal detection including two bottlenose dolphins (under water) and three California sea lions (in air). Median RT increased exponentially with decreased SPL in all cases. Equal-latency contours for near-threshold RTs were similar to audiograms in both species. Data for the sea lions showed some compression of equal-latency contours with increases in SPL; however, large inter-subject differences in the data for dolphins made results for that species more difficult to interpret. The equal-latency contours for all subjects progressively diverged from predicted equal-loudness contours at higher SPLs, likely a result of very small changes in RT with relatively large increases in SPL. As a result, the contours of most interest for designing weighting functions for high-level noise exposures were also the least reliable. The general similarity of most of the contours to species-typical audiograms suggests that more easily obtained auditory thresholds may provide useful approximations for weighting. [Funded by U.S. Navy Living Marine Resources Program.]
    No preview · Article · Apr 2015 · The Journal of the Acoustical Society of America
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    ABSTRACT: Bottlenose dolphins performing echolocation tasks at long ranges may utilize a transmission mode where bursts, or "packets," of echolocation clicks are emitted rather than single clicks. The clicks within each packet are separated by time intervals well below the two-way travel time, while the packets themselves are emitted at intervals greater than the two-way travel time. Packet use has been shown to increase with range; however, the exact function of packets and the advantages gained by their utilization remain unknown. In this study, the capability for dolphins to utilize multi-echo processing within packets of echoes was investigated by manipulating the number of available echoes within each packet as a dolphin performed a long-range echolocation task. The results showed an improvement in detectability with an increase in the number of echoes in each packet and suggest that packet use is an adaptation to allow multi-echo processing at long ranges without introducing range ambiguity.
    No preview · Article · Nov 2014 · The Journal of the Acoustical Society of America
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    ABSTRACT: Previous measurements of toothed whale echolocation transmission beam patterns have utilized few hydrophones and have therefore been limited to fine angular resolution only near the principal axis or poor resolution over larger azimuthal ranges. In this study, a circular, horizontal planar array of 35 hydrophones was used to measure a dolphin's transmission beam pattern with 5° to 10° resolution at azimuths from -150° to +150°. Beam patterns and directivity indices were calculated from both the peak-peak sound pressure and the energy flux density. The emitted pulse became smaller in amplitude and progressively distorted as it was recorded farther off the principal axis. Beyond ±30° to 40°, the off-axis signal consisted of two distinct pulses whose difference in time of arrival increased with the absolute value of the azimuthal angle. A simple model suggests that the second pulse is best explained as a reflection from internal structures in the dolphin's head, and does not implicate the use of a second sound source. Click energy was also more directional at the higher source levels utilized at longer ranges, where the center frequency was elevated compared to that of the lower amplitude clicks used at shorter range.
    Full-text · Article · Oct 2014 · The Journal of the Acoustical Society of America
  • Jason Mulsow · James J Finneran · Dorian S Houser
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    ABSTRACT: Suction cup transducers, also known as "jawphones," are now commonly used to deliver acoustic stimuli to odontocete cetaceans during hearing studies. It is often assumed that stimulation is primarily limited to the ear ipsilateral to a jawphone; however, the actual differences in auditory stimulation at the two ears are not well understood. To examine these differences, auditory evoked potentials (AEPs) were simultaneously recorded from both ears during jawphone stimulation in two bottlenose dolphins. The amplitudes and latencies of auditory nerve responses (ANRs) elicited by broadband clicks were measured as functions of stimulus level and used to estimate the difference in received level and interaural time difference (ITD) between the two ears. Results indicated that clicks received at the ear contralateral to the jawphone were attenuated by approximately 20 dB relative to the level at the ipsilateral ear. The ITD between the contralateral and ipsilateral ears was 70 μs for the first dolphin and 118 μs for the second dolphin. While these results provide support for a notable degree of acoustic isolation of the ears for jawphone-delivered stimuli, there are implications for studies involving processes such as sound localization and unilateral hearing loss.
    No preview · Article · Sep 2014 · The Journal of the Acoustical Society of America
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    ABSTRACT: It has been proposed that two pairs of phonic lips might be utilized by a dolphin to adaptively manipulate the frequency content and directionality of the echolocation beam in response to acquired target information. The presence of two pulses appearing off-axis of the echolocation beam and separated in time has been proposed as evidence supporting this hypothesis. An array containing 35 hydrophones was used to measure the beam pattern of a bottlenose dolphin performing a phantom echo-change detection task. Simulated target ranges varied from 2.5 to 80 m and clicks were measured at 5-10° resolution from + /150°. At recording angles beyond + /30°, the click appeared as two distinct pulses that declined in amplitude and distorted as the off-axis angle increased. A simple model utilizing the time difference of arrival for the two pulses was used to compare the direct source-receiver path to one of two source-reflector-receiver paths. Assuming a range of constant sound speeds, distances traveled were compared to a CT scan of the same animal to predict anatomical regions potentially contributing to the second pulse. Results suggest that the second pulse is due to reflections from internal structures of the dolphin head and not a second sound source.
    Full-text · Article · Apr 2014 · The Journal of the Acoustical Society of America
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    ABSTRACT: Dolphins are social animals that rely heavily on passive and active acoustics for communication, navigation, foraging, and detecting predators. Auditory masking, from both natural and anthropogenic noise sources, may adversely affect these fitness-related capabilities. The dolphin's ability to detect a variety of complex signals (both dolphin phonations and tonal signals) masked by Gaussian, comodulated, snapping shrimp, and ice squeaks noise was tested. Detection thresholds were measured using a go/no-go adaptive staircase procedure. Masking patterns were similar for all signals (whistles, burst-pulse, and pure tones) except for click signals. Masking from ice squeaks resulted in the largest masked thresholds, while snapping shrimp and comodulated noise resulted in a release from masking relative to thresholds from Gaussian noise. Click signals were most difficult to detect when masked by snapping shrimp. Recognition thresholds were estimated for whistle-like signals using a cross-modal, matching-to-sample procedure. Recognition thresholds were on average 4 dB greater than detection thresholds for all noise types. The auditory mechanisms governing the results are discussed. [Work supported by the ONR.].
    No preview · Article · Apr 2014 · The Journal of the Acoustical Society of America
  • James J Finneran · Jason Mulsow · Dorian S Houser
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    ABSTRACT: Phantom echo generation replaces physical targets with electronic signals that can be delayed in time, scaled in amplitude, and broadcast to an echolocating animal to simulate echoes from distant objects. Compared to physical targets, phantom echoes have the advantages of allowing for instantaneous changes in target characteristics, independent manipulation of echo delay and echo amplitude, and easy randomization of target range. At the Navy Marine Mammal Program in San Diego, California, phantom echo generation is combined with measurements of auditory evoked potentials to investigate the temporal dynamics of biosonar signal emission and reception in bottlenose dolphins. The studies are primarily focused on examining automatic gain control mechanisms by measuring changes in hearing sensitivity - assessed via the auditory steady-state response (ASSR) to an amplitude modulated tone - over time courses corresponding to single biosonar click-echo pairs. Results show the ASSR amplitude initially decreases at the time of click emission and then recovers following click emission, with the time course of recovery related to target range, click amplitude, and tone frequency. Additional studies are focused on dynamic changes in click emissions that occur with changes in target range. [Work funded by SSC Pacific Naval Innovative Science and Engineering (NISE) program.].
    No preview · Article · Apr 2014 · The Journal of the Acoustical Society of America
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    ABSTRACT: In-air anthropogenic sound has the potential to affect grey seal (Halichoerus grypus) behaviour and interfere with acoustic communication. In this study, a new method was used to deliver acoustic signals to grey seals as part of an in-air hearing assessment. Using in-ear headphones with adapted ear inserts allowed for the measurement of auditory brainstem responses (ABR) on sedated grey seals exposed to 5-cycle (2-1-2) tone pips. Thresholds were measured at 10 frequencies between 1-20 kHz. Measurements were made using subcutaneous electrodes on wild seals from the Baltic and North Seas. Thresholds were determined by both visual and statistical approaches (single point F-test) and good agreement was obtained between the results using both methods. The mean auditory thresholds were ≤40 dB re 20 µPa peak equivalent sound pressure level (peSPL) between 4-20 kHz and showed similar patterns to in-air behavioural hearing tests of other phocid seals between 3 and 20 kHz. Below 3 kHz, a steep reduction in hearing sensitivity was observed, which differed from the rate of decline in sensitivity obtained in behavioural studies on other phocids. Differences in the rate of decline may reflect influence of the ear inserts on the ability to reliably transmit lower frequencies or interference from the structure of the distal end of the ear canal.
    Full-text · Article · Mar 2014 · PLoS ONE

Publication Stats

2k Citations
273.12 Total Impact Points

Institutions

  • 2008-2015
    • United States Navy
      • Space and Naval Warfare Systems Center
      Monterey, California, United States
    • University of Hawai'i System
      Honolulu, Hawaii, United States
    • University of Hawaiʻi at Hilo
      Hilo, Hawaii, United States
  • 2003-2015
    • Navy's Space and Naval Warfare Systems Command
      San Diego, California, United States
  • 2012-2013
    • National Marine Mammal Foundation
      San Diego, California, United States
  • 2011
    • Naval Undersea Warfare Center
      Newport, Rhode Island, United States
  • 1996-2004
    • The Ohio State University
      • Department of Mechanical and Aerospace Engineering
      Columbus, Ohio, United States