How spatial release from masking may fail to function in a highly directional auditory system
- University of Toronto Scarborough, Canada
Figures
Figure 1
Signal and masker and experimental setup used in recording walking phonotaxis.
(A) Gravid female Ormia ochracea tethered on top of the treadmill system and positioned equidistant (Experiments 1 and 3: 20 cm, Experiment 2: 10 cm) from surrounding speakers. The target signal …
Figure 2
Walking phonotaxis in response to the target signal and masker in isolation.
Mean (solid lines) and SEM (dotted lines) of (A) forward and (B) steering velocity components from walking phonotaxis in response to a forward (0°azimuth) target signal (black) or masker (red) …
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Figure 2—source data 1
Translational velocity in response to the target signal and masker presented in isolation.
Masker presentation started and ended 0.5 and 4.5 s after the onset of data acquisition, respectively. Signal presentation started and ended 1.0 and 4.0 s after the onset of data acquisition, respectively. Data plotted in Figure 2A.
- https://doi.org/10.7554/eLife.20731.004
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Figure 2—source data 2
Steering velocity in response to the target signal and masker presented in isolation.
Masker presentation started and ended 0.5 and 4.5 s after the onset of data acquisition, respectively. Signal presentation started and ended 1.0 and 4.0 s after the onset of data acquisition, respectively. Data plotted in Figure 2B.
- https://doi.org/10.7554/eLife.20731.005
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Figure 2—source data 3
Virtual walking path in response to the target signal and masker presented in isolation.
‘X’ and ‘Y’ coordinates of virtual walking paths measured from the treadmill system. Data plotted in Figure 2C.
- https://doi.org/10.7554/eLife.20731.006
Figure 3
Spatial separation between target signal and masker does not decrease behavioural response thresholds.
Estimated behavioural response thresholds in quiet, with a target signal and masker separated by 6°, or 90°. Box plots depict first, second (median), and third quartiles. Whiskers depict 1.5 × …
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Figure 3—source data 1
Behavioral response thresholds to a target signal in quiet, and signal and masker separated by 6° or 90°.
Data plotted in figure.
- https://doi.org/10.7554/eLife.20731.008
Figure 4
Effects of spatial separation and signal-to-noise ratio on sound localization.
Mean (solid lines) and SEM (dotted lines) of (A) forward and (B) steering velocity components to a 76 dB SPL target signal alone (black trace) or signal and masker broadcasted at SNRs of −6 dB …
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Figure 4—source data 1
Translational velocity in response to a target signal and masker separated by 6° and presented at different signal-to-noise ratios (SNRs).
The target signal was presented at 76 dB SPL while the masker intensity was varied to achieve three SNRs (−6, 0, +6 dB). Masker presentation started and ended 0.5 and 4.5 s after the onset of data acquisition, respectively. Signal presentation started and ended 1.0 and 4.0 s after the onset of data acquisition, respectively. Data plotted in Figure 4A (left).
- https://doi.org/10.7554/eLife.20731.010
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Figure 4—source data 2
Steering velocity in response to a target signal and masker separated by 6° and presented at different signal-to-noise ratios (SNRs).
The target signal was presented at 76 dB SPL while the masker intensity was varied to achieve three SNRs (−6, 0, +6 dB). Masker presentation started and ended 0.5 and 4.5 s after the onset of data acquisition, respectively. Signal presentation started and ended 1.0 and 4.0 s after the onset of data acquisition, respectively. Data plotted in Figure 4B (left).
- https://doi.org/10.7554/eLife.20731.011
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Figure 4—source data 3
Virtual walking path in response to a target signal and masker separated by 6° and presented at different signal-to-noise ratios (SNRs).
The target signal was presented at 76 dB SPL while the masker intensity was varied to achieve three SNRs (−6, 0, +6 dB). ‘X’ and ‘Y’ coordinates of virtual walking paths measured from the treadmill system. Data plotted in Figure 4C (left).
- https://doi.org/10.7554/eLife.20731.012
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Figure 4—source data 4
Translational velocity in response to a target signal and masker separated by 90° and presented at different signal-to-noise ratios (SNRs).
The target signal was presented at 76 dB SPL while the masker intensity was varied to achieve three SNRs (−6, 0, +6 dB). Masker presentation started and ended 0.5 and 4.5 s after the onset of data acquisition respectively. Signal presentation started and ended 1.0 and 4.0 s after the onset of data acquisition, respectively. Data plotted in Figure 4A (right).
- https://doi.org/10.7554/eLife.20731.013
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Figure 4—source data 5
Steering velocity in response to a target signal and masker separated by 90° and presented at different signal-to-noise ratios (SNRs).
The target signal was presented at 76 dB SPL while the masker intensity was varied to achieve three SNRs (−6, 0, +6 dB). Masker presentation started and ended 0.5 and 4.5 s after the onset of data acquisition respectively. Signal presentation started and ended 1.0 and 4.0 s after the onset of data acquisition, respectively. Data plotted in Figure 4B (right).
- https://doi.org/10.7554/eLife.20731.014
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Figure 4—source data 6
Virtual walking path in response to a target signal and masker separated by 90° and presented at different signal-to-noise ratios (SNRs).
The target signal was presented at 76 dB SPL while the masker intensity was varied to achieve three SNRs (−6, 0, +6 dB). ‘X’ and ‘Y’ coordinates of virtual walking paths measured from the treadmill system. Data plotted in Figure 4C (right).
- https://doi.org/10.7554/eLife.20731.015
Figure 5
Virtual walking trajectories in response to asymmetrical and symmetrical auditory input.
Attractive target signal and masker broadcast at 76 dB SPL. Plots represent average walking responses ± SEM to a frontal signal broadcast (A) in isolation, or with (B) a masker in close proximity to …
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Figure 5—source data 1
Virtual walking path in response to the target signal presented in isolation.
The target signal was presented at 76 dB SPL from a forward speaker. ‘X’ and ‘Y’ coordinates of virtual walking paths measured from the treadmill system. Data plotted in Figure 5A.
- https://doi.org/10.7554/eLife.20731.017
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Figure 5—source data 2
Virtual walking path in response to a target signal and masker (on the right) separated by 6° and presented at equal intensity.
The target signal was presented at 76 dB SPL from a forward speaker while the masker was presented at the same intensity from an adjacent speaker to the right. ‘X’ and ‘Y’ coordinates of virtual walking paths measured from the treadmill system. Data plotted in Figure 5B.
- https://doi.org/10.7554/eLife.20731.018
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Figure 5—source data 3
Virtual walking path in response to a target signal and masker (on the left) separated by 6° and presented at equal intensity.
The target signal was presented at 76 dB SPL from a forward speaker while the masker was presented at the same intensity from an adjacent speaker to the left. ‘X’ and ‘Y’ coordinates of virtual walking paths measured from the treadmill system. Data plotted in Figure 5C.
- https://doi.org/10.7554/eLife.20731.019
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Figure 5—source data 4
Virtual walking path in response to a target signal and maskers separated by 6° and presented at equal intensity.
The target signal was presented at 76 dB SPL from a forward speaker while two coherent maskers were presented at the same combined intensity from adjacent speakers to the left and right of the signal speaker. ‘X’ and ‘Y’ coordinates of virtual walking paths measured from the treadmill system. Data plotted in Figure 5D.
- https://doi.org/10.7554/eLife.20731.020
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Figure 5—source data 5
Virtual walking path in response to a target signal and masker (on the right) separated by 90° and presented at equal intensity.
The target signal was presented at 76 dB SPL from a forward speaker while the masker was presented at the same intensity from a lateral speaker to the right. ‘X’ and ‘Y’ coordinates of virtual walking paths measured from the treadmill system. Data plotted in Figure 5E.
- https://doi.org/10.7554/eLife.20731.021
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Figure 5—source data 6
Virtual walking path in response to a target signal and masker (on the left) separated by 90° and presented at equal intensity.
The target signal was presented at 76 dB SPL from a forward speaker while the masker was presented at the same intensity from a lateral speaker to the left. ‘X’ and ‘Y’ coordinates of virtual walking paths measured from the treadmill system. Data plotted in Figure 5F.
- https://doi.org/10.7554/eLife.20731.022
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Figure 5—source data 7
Virtual walking path in response to target signal and maskers that are separated by 90° and presented at equal intensity.
The target signal was presented at 76 dB SPL from a forward speaker while two coherent maskers were presented at the same combined intensity from lateral speakers to the left and right of the signal speaker. ‘X’ and ‘Y’ coordinates of virtual walking paths measured from the treadmill system. Data plotted in Figure 5G.
- https://doi.org/10.7554/eLife.20731.023
Figure 6
Effects of spatial separation on tympanal vibration.
(A) Exemplar vibration measurements to illustrate the effective amplitude, which is the signal driven response that is above the masker-driven response. Measurement (smoothed with a sliding RMS …
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Figure 6—source data 1
Raw traces of tympanal vibration in response to combined signal and masker under conditions of masker source located near (separated by 6°) or far (separated by 90°) from signal source.
Ipsi- and contralateral refer to the masker. Signal pulses were repeated at 400 ms intervals during continuous masker broadcast.
- https://doi.org/10.7554/eLife.20731.025
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Figure 6—source data 2
Normalized-amplitude tympanal vibration responses.
Vibration measurements are normalized to the peak response in response to the target signal. Data plotted in Figure 6B,C.
- https://doi.org/10.7554/eLife.20731.026
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Figure 6—source data 3
Smoothed tympanal vibration responses.
Measurements smoothed with a 2000-point sliding rms window.
- https://doi.org/10.7554/eLife.20731.027
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Figure 6—source data 4
Effective amplitude measurements.
Effective amplitude measurements (i.e. within-trace signal-to-noise ratio) from smoothed tympanal responses for 23 iterations of signal within the masker. Signal amplitudes were measured from 30 ms time segments corresponding with signal pulses; masker amplitudes were measured from 30 ms segments in the middle of the interpulse interval (i.e. 200 ms after signal-pulse onset). Data plotted in Figure 6D.
- https://doi.org/10.7554/eLife.20731.028
Figure 7
Tympanal interaural vibration amplitude difference predict error in sound localization.
(A) Effective vibration amplitudes measured in LDV experiments to a target signal broadcast simultaneously with an ipsilateral (blue) or contralateral (red) masker at varied SNRs. (B) Effective inter…
Figure 8
Better signal detection in the masker-contralateral ear.
(A) Exemplar multi-unit recordings from the both sides of the auditory system in response to signal and masker with a 90° spatial separation. Inset (black) shows the time course of the stimulation …
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Figure 8—source data 1
Root Mean Square (RMS) values calculated from multiunit recordings of left and right auditory nerve.
RMS calculated over 40 ms time segments during an interval with a target signal and masker separated by 90° and broadcast at varied signal-to-noise ratios (−18, –12, −6, 0, +6 dB), and an equivalent time window during masker broadcast alone. Signal detection theory was applied to RMS measurements to determine masked thresholds for the masker ipsi- and contralateral ears. These data are plotted in Figure 8C.
- https://doi.org/10.7554/eLife.20731.031
Figure 9
Current model of diverted walking phonotaxis in Ormia ochracea.
(A) 6° and (B) 90° spatial separations between the target signal (cricket song) and masker (band-limited noise). The forward target signal results in equal (symmetrical) stimulation to both tympana …
