scholarly journals Auditory Attention and Spatial Unmasking in Children With Cochlear Implants

2020 ◽  
Vol 24 ◽  
pp. 233121652094698
Author(s):  
Sara M. Misurelli ◽  
Matthew J. Goupell ◽  
Emily A. Burg ◽  
Rachael Jocewicz ◽  
Alan Kan ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
Free Field ◽  
Auditory Attention ◽  
Noisy Environments ◽  
Speech Stimuli ◽  
Bilateral Cochlear Implants ◽  
Speech Reception ◽  
Spatial Unmasking ◽  
Speech Reception Thresholds ◽  
Hearing Children

The ability to attend to target speech in background noise is an important skill, particularly for children who spend many hours in noisy environments. Intelligibility improves as a result of spatial or binaural unmasking in the free-field for normal-hearing children; however, children who use bilateral cochlear implants (BiCIs) demonstrate little benefit in similar situations. It was hypothesized that poor auditory attention abilities might explain the lack of unmasking observed in children with BiCIs. Target and interferer speech stimuli were presented to either or both ears of BiCI participants via their clinical processors. Speech reception thresholds remained low when the target and interferer were in opposite ears, but they did not show binaural unmasking when the interferer was presented to both ears and the target only to one ear. These results demonstrate that, in the most extreme cases of stimulus separation, children with BiCIs can ignore an interferer and attend to target speech, but there is weak or absent binaural unmasking. It appears that children with BiCIs mostly experience poor encoding of binaural cues rather than deficits in ability to selectively attend to target speech.

scholarly journals Spatial Unmasking Effect on Speech Reception Threshold in the Median Plane

2020 ◽  
Vol 10 (15) ◽  
pp. 5257
Author(s):  
Nathan Berwick ◽  
Hyunkook Lee
Keyword(s):  
Transfer Function ◽  
Input Signal ◽  
Function Analysis ◽  
Median Plane ◽  
Speech Reception ◽  
Transfer Function Analysis ◽  
Spatial Unmasking ◽  
Head Related Transfer Function ◽  
Speech Reception Thresholds ◽  
Energy Weighting

This study examined whether the spatial unmasking effect operates on speech reception thresholds (SRTs) in the median plane. SRTs were measured using an adaptive staircase procedure, with target speech sentences and speech-shaped noise maskers presented via loudspeakers at −30°, 0°, 30°, 60° and 90°. Results indicated a significant median plane spatial unmasking effect, with the largest SRT gain obtained for the −30° elevation of the masker. Head-related transfer function analysis suggests that the result is associated with the energy weighting of the ear-input signal of the masker at upper-mid frequencies relative to the maskee.

scholarly journals Studies on Bilateral Cochlear Implants at the University of Wisconsin’s Binaural Hearing and Speech Laboratory

2012 ◽  
Vol 23 (06) ◽  
pp. 476-494 ◽  
Author(s):  
Ruth Y. Litovsky ◽  
Matthew J. Goupell ◽  
Shelly Godar ◽  
Tina Grieco-Calub ◽  
Gary L. Jones ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
Age At Onset ◽  
Free Field ◽  
Spatial Hearing ◽  
Binaural Hearing ◽  
Systematic Investigation ◽  
Spatial Cues ◽  
Bilateral Cochlear Implants ◽  
Adults And Children ◽  
The Impact

This report highlights research projects relevant to binaural and spatial hearing in adults and children. In the past decade we have made progress in understanding the impact of bilateral cochlear implants (BiCIs) on performance in adults and children. However, BiCI users typically do not perform as well as normal hearing (NH) listeners. In this article we describe the benefits from BiCIs compared with a single cochlear implant (CI), focusing on measures of spatial hearing and speech understanding in noise. We highlight the fact that in BiCI listening the devices in the two ears are not coordinated; thus binaural spatial cues that are available to NH listeners are not available to BiCI users. Through the use of research processors that carefully control the stimulus delivered to each electrode in each ear, we are able to preserve binaural cues and deliver them with fidelity to BiCI users. Results from those studies are discussed as well, with a focus on the effect of age at onset of deafness and plasticity of binaural sensitivity. Our work with children has expanded both in number of subjects tested and age range included. We have now tested dozens of children ranging in age from 2 to 14 yr. Our findings suggest that spatial hearing abilities emerge with bilateral experience. While we originally focused on studying performance in free field, where real world listening experiments are conducted, more recently we have begun to conduct studies under carefully controlled binaural stimulation conditions with children as well. We have also studied language acquisition and speech perception and production in young CI users. Finally, a running theme of this research program is the systematic investigation of the numerous factors that contribute to spatial and binaural hearing in BiCI users. By using CI simulations (with vocoders) and studying NH listeners under degraded listening conditions, we are able to tease apart limitations due to the hardware/software of the CI systems from limitations due to neural pathology.

A Tangibly Reinforced Speech Reception Threshold Procedure for Use with Small Children

1976 ◽  
Vol 41 (3) ◽  
pp. 333-338
Author(s):  
Frederick N. Martin ◽  
Sherry Coombes
Keyword(s):  
Operant Conditioning ◽  
Sound Field ◽  
Normal Hearing ◽  
New Method ◽  
Small Children ◽  
Field System ◽  
Speech Reception ◽  
Threshold Procedure ◽  
Speech Reception Thresholds ◽  
Hearing Children

Forty normal-hearing children between 17 and 56 months were tested using a new method for determining speech reception thresholds. The words employed were names for parts of a device that was in the form of a colorful clown. The device automatically rewarded the child with a small piece of candy each time he pressed the part of the clown that had been announced through the sound field system of a speech audiometer. Results showed that operant conditioning speech audiometry using tangible reinforcers is feasible for small children. Both boys and girls can be tested accurately by this method down to age two and one-half years.

scholarly journals Binaural (pre)processing for contralateral sound field attenuation and improved speech-in-noise recognition

2021 ◽  
Author(s):  
Enrique A. Lopez-Poveda ◽  
Almudena Eustaquio-Martín ◽  
Fernando Martín San Victoriano
Keyword(s):  
Sound Source ◽  
Transfer Functions ◽  
Signal To Noise Ratio ◽  
Free Field ◽  
Sound Field ◽  
Directivity Pattern ◽  
Sound Sources ◽  
Speech In Noise ◽  
Speech Reception ◽  
Speech Reception Thresholds

ABSTRACTUnderstanding speech presented in competition with other sound sources can be challenging. Here, we reason that this task can be facilitated by improving the signal-to-noise ratio (SNR) in either of the two ears and that in free-field listening scenarios, this can be achieved by attenuating contralateral sounds. We present a binaural (pre)processing algorithm that improves the SNR in the ear ipsilateral to the target sound source by linear subtraction of the weighted contralateral stimulus. Although the weight is regarded as a free parameter, we justify setting it equal to the ratio of ipsilateral to contralateral head-related transfer functions averaged over an appropriate azimuth range. The algorithm is implemented in the frequency domain and evaluated technically and experimentally for normal-hearing listeners in simulated free-field conditions. Results show that (1) it can substantially improve the SNR (up to 20 dB) and the short-term intelligibility metric in the ear ipsilateral to the target source, particularly for speech-like maskers; (2) it can improve speech reception thresholds for sentences in competition with speech-shaped noise by up to 8.5 dB in bilateral listening and 10.0 dB in unilateral listening; (3) it hardly affects sound-source localization; and (4) the improvements, and the algorithm’s directivity pattern depend on the weights. The algorithm accounts qualitatively for binaural unmasking for speech in competition with multiple maskers and for multiple target-masker spatial arrangements, an unexpected property that can inspire binaural intelligibility models.

Sign in / Sign up

Export Citation Format

Share Document