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Impact of a moving noise masker on speech perception in cochlear implant users.

Weissgerber T, Rader T, Baumann U - PLoS ONE (2015)

Bottom Line: There was no effect of subject group.A significant effect of directional sensitivity was found in the S0Nmove setup.Users of bilateral speech processors with both directional microphones obtained the highest benefit.

View Article: PubMed Central - PubMed

Affiliation: Audiological Acoustics, ENT Department, University Hospital Frankfurt, Frankfurt am Main, Germany.

ABSTRACT

Objectives: Previous studies investigating speech perception in noise have typically been conducted with static masker positions. The aim of this study was to investigate the effect of spatial separation of source and masker (spatial release from masking, SRM) in a moving masker setup and to evaluate the impact of adaptive beamforming in comparison with fixed directional microphones in cochlear implant (CI) users.

Design: Speech reception thresholds (SRT) were measured in S0N0 and in a moving masker setup (S0Nmove) in 12 normal hearing participants and 14 CI users (7 subjects bilateral, 7 bimodal with a hearing aid in the contralateral ear). Speech processor settings were a moderately directional microphone, a fixed beamformer, or an adaptive beamformer. The moving noise source was generated by means of wave field synthesis and was smoothly moved in a shape of a half-circle from one ear to the contralateral ear. Noise was presented in either of two conditions: continuous or modulated.

Results: SRTs in the S0Nmove setup were significantly improved compared to the S0N0 setup for both the normal hearing control group and the bilateral group in continuous noise, and for the control group in modulated noise. There was no effect of subject group. A significant effect of directional sensitivity was found in the S0Nmove setup. In the bilateral group, the adaptive beamformer achieved lower SRTs than the fixed beamformer setting. Adaptive beamforming improved SRT in both CI user groups substantially by about 3 dB (bimodal group) and 8 dB (bilateral group) depending on masker type.

Conclusions: CI users showed SRM that was comparable to normal hearing subjects. In listening situations of everyday life with spatial separation of source and masker, directional microphones significantly improved speech perception with individual improvements of up to 15 dB SNR. Users of bilateral speech processors with both directional microphones obtained the highest benefit.

No MeSH data available.


Related in: MedlinePlus

Speech reception thresholds (SRTs) of all participants in all test conditions.CI users were tested with standard directional setting. The asterisks indicate a statistically significant difference in SRT between S0N0 and S0Nmove (*p < 0.05, **p < 0.01, ***p < 0.001).
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pone.0126133.g004: Speech reception thresholds (SRTs) of all participants in all test conditions.CI users were tested with standard directional setting. The asterisks indicate a statistically significant difference in SRT between S0N0 and S0Nmove (*p < 0.05, **p < 0.01, ***p < 0.001).

Mentions: Median, interquartile, and range values of SRT measurements of the normal hearing group and CI users with directivity setting standard in S0N0 and S0Nmove setups are shown in Fig 4. As the y axis is inverted, higher performance (lower SRT) is depicted by “higher” boxplots. Outliers (defined as data points more than 1.5 box-lengths away from the median) are indicated by crosses. Individual results of the normal hearing group are shown in the S1 Table.


Impact of a moving noise masker on speech perception in cochlear implant users.

Weissgerber T, Rader T, Baumann U - PLoS ONE (2015)

Speech reception thresholds (SRTs) of all participants in all test conditions.CI users were tested with standard directional setting. The asterisks indicate a statistically significant difference in SRT between S0N0 and S0Nmove (*p < 0.05, **p < 0.01, ***p < 0.001).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4430230&req=5

pone.0126133.g004: Speech reception thresholds (SRTs) of all participants in all test conditions.CI users were tested with standard directional setting. The asterisks indicate a statistically significant difference in SRT between S0N0 and S0Nmove (*p < 0.05, **p < 0.01, ***p < 0.001).
Mentions: Median, interquartile, and range values of SRT measurements of the normal hearing group and CI users with directivity setting standard in S0N0 and S0Nmove setups are shown in Fig 4. As the y axis is inverted, higher performance (lower SRT) is depicted by “higher” boxplots. Outliers (defined as data points more than 1.5 box-lengths away from the median) are indicated by crosses. Individual results of the normal hearing group are shown in the S1 Table.

Bottom Line: There was no effect of subject group.A significant effect of directional sensitivity was found in the S0Nmove setup.Users of bilateral speech processors with both directional microphones obtained the highest benefit.

View Article: PubMed Central - PubMed

Affiliation: Audiological Acoustics, ENT Department, University Hospital Frankfurt, Frankfurt am Main, Germany.

ABSTRACT

Objectives: Previous studies investigating speech perception in noise have typically been conducted with static masker positions. The aim of this study was to investigate the effect of spatial separation of source and masker (spatial release from masking, SRM) in a moving masker setup and to evaluate the impact of adaptive beamforming in comparison with fixed directional microphones in cochlear implant (CI) users.

Design: Speech reception thresholds (SRT) were measured in S0N0 and in a moving masker setup (S0Nmove) in 12 normal hearing participants and 14 CI users (7 subjects bilateral, 7 bimodal with a hearing aid in the contralateral ear). Speech processor settings were a moderately directional microphone, a fixed beamformer, or an adaptive beamformer. The moving noise source was generated by means of wave field synthesis and was smoothly moved in a shape of a half-circle from one ear to the contralateral ear. Noise was presented in either of two conditions: continuous or modulated.

Results: SRTs in the S0Nmove setup were significantly improved compared to the S0N0 setup for both the normal hearing control group and the bilateral group in continuous noise, and for the control group in modulated noise. There was no effect of subject group. A significant effect of directional sensitivity was found in the S0Nmove setup. In the bilateral group, the adaptive beamformer achieved lower SRTs than the fixed beamformer setting. Adaptive beamforming improved SRT in both CI user groups substantially by about 3 dB (bimodal group) and 8 dB (bilateral group) depending on masker type.

Conclusions: CI users showed SRM that was comparable to normal hearing subjects. In listening situations of everyday life with spatial separation of source and masker, directional microphones significantly improved speech perception with individual improvements of up to 15 dB SNR. Users of bilateral speech processors with both directional microphones obtained the highest benefit.

No MeSH data available.


Related in: MedlinePlus