Importance of low frequency hearing for spatial release from masking

2018 ◽  
Vol 143 (3) ◽  
pp. 1938-1938
Author(s):  
Nirmal Kumar Srinivasan ◽  
Maxwell Schmidt ◽  
Alexis Staudenmeier ◽  
Kelli Clark
Keyword(s):  
Low Frequency ◽  
Spatial Release ◽  
Release From Masking

scholarly journals Spatial Release From Masking in Simulated Cochlear Implant Users With and Without Access to Low-Frequency Acoustic Hearing

2015 ◽  
Vol 19 ◽  
pp. 233121651561694 ◽  
Author(s):  
Ben Williges ◽  
Mathias Dietz ◽  
Volker Hohmann ◽  
Tim Jürgens
Keyword(s):  
Cochlear Implant ◽  
Low Frequency ◽  
Spatial Release ◽  
Acoustic Hearing ◽  
Release From Masking

scholarly journals Neural Correlates and Mechanisms of Spatial Release From Masking: Single-Unit and Population Responses in the Inferior Colliculus

2005 ◽  
Vol 94 (2) ◽  
pp. 1180-1198 ◽  
Author(s):  
Courtney C. Lane ◽  
Bertrand Delgutte
Keyword(s):  
Inferior Colliculus ◽  
Single Unit ◽  
Signal To Noise Ratio ◽  
Low Frequency ◽  
Broadband Noise ◽  
Auditory Signal ◽  
Spatial Release ◽  
Additional Processing ◽  
Release From Masking ◽  
Correlator Model

Spatial release from masking (SRM), a factor in listening in noisy environments, is the improvement in auditory signal detection obtained when a signal is separated in space from a masker. To study the neural mechanisms of SRM, we recorded from single units in the inferior colliculus (IC) of barbiturate-anesthetized cats, focusing on low-frequency neurons sensitive to interaural time differences. The stimulus was a broadband chirp train with a 40-Hz repetition rate in continuous broadband noise, and the unit responses were measured for several signal and masker (virtual) locations. Masked thresholds (the lowest signal-to-noise ratio, SNR, for which the signal could be detected for 75% of the stimulus presentations) changed systematically with signal and masker location. Single-unit thresholds did not necessarily improve with signal and masker separation; instead, they tended to reflect the units' azimuth preference. Both how the signal was detected (through a rate increase or decrease) and how the noise masked the signal response (suppressive or excitatory masking) changed with signal and masker azimuth, consistent with a cross-correlator model of binaural processing. However, additional processing, perhaps related to the signal's amplitude modulation rate, appeared to influence the units' responses. The population masked thresholds (the most sensitive unit's threshold at each signal and masker location) did improve with signal and masker separation as a result of the variety of azimuth preferences in our unit sample. The population thresholds were similar to human behavioral thresholds in both SNR value and shape, indicating that these units may provide a neural substrate for low-frequency SRM.

scholarly journals Impacts of Diabetes, Aging, and Hearing Loss on Speech-on-Speech Masking and Spatial Release in a Large Veteran Cohort

2021 ◽  
pp. 1-14
Author(s):  
Sarah M. Theodoroff ◽  
Frederick J. Gallun ◽  
Garnett P. McMillan ◽  
Michelle Molis ◽  
Nirmal Srinivasan ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Pure Tone ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Low Frequency ◽  
Correct Identification ◽  
Speech Understanding ◽  
Impaired Hearing ◽  
Pure Tone Average ◽  
Spatial Release

Purpose Type 2 diabetes mellitus (DM2) is associated with impaired hearing. However, the evidence is less clear if DM2 can lead to difficulty understanding speech in complex acoustic environments, independently of age and hearing loss effects. The purpose of this study was to estimate the magnitude of DM2-related effects on speech understanding in the presence of competing speech after adjusting for age and hearing. Method A cross-sectional study design was used to investigate the relationship between DM2 and speech understanding in 190 Veterans ( M age = 47 years, range: 25–76). Participants were classified as having no diabetes ( n = 74), prediabetes ( n = 19), or DM2 that was well controlled ( n = 24) or poorly controlled ( n = 73). A test of spatial release from masking (SRM) was presented in a virtual acoustical simulation over insert earphones with multiple talkers using sentences from the coordinate response measure corpus to determine the target-to-masker ratio (TMR) required for 50% correct identification of target speech. A linear mixed model of the TMR results was used to estimate SRM and separate effects of diabetes group, age, and low-frequency pure-tone average (PTA-low) and high-frequency pure-tone average. A separate model estimated the effects of DM2 on PTA-low. Results After adjusting for hearing and age, diabetes-related effects remained among those whose DM2 was well controlled, showing an SRM loss of approximately 0.5 dB. Results also showed effects of hearing loss and age, consistent with the literature on people without DM2. Low-frequency hearing loss was greater among those with DM2. Conclusions In a large cohort of Veterans, low-frequency hearing loss and older age negatively impact speech understanding. Compared with nondiabetics, individuals with controlled DM2 have additional auditory deficits beyond those associated with hearing loss or aging. These results provide a potential explanation for why individuals who have diabetes and/or are older often report difficulty understanding speech in real-world listening environments. Supplemental Material https://doi.org/10.23641/asha.16746475

scholarly journals Verification of an automated headphone-based test of spatial release from masking

2016 ◽  
Author(s):  
Frederick J. Gallun ◽  
Garnett P. McMillan ◽  
Sean D. Kampel ◽  
Kasey M. Jakien ◽  
Nirmal K. Srinivasan ◽  
...  
Keyword(s):  
Spatial Release ◽  
Release From Masking

scholarly journals FreeHear: A New Sound-Field Speech-in-Babble Hearing Assessment Tool

2019 ◽  
Vol 23 ◽  
pp. 233121651987237 ◽  
Author(s):  
David R. Moore ◽  
Helen Whiston ◽  
Melanie Lough ◽  
Antonia Marsden ◽  
Harvey Dillon ◽  
...  
Keyword(s):  
Assessment Tool ◽  
Sound Field ◽  
Standard Test ◽  
Initial Assessment ◽  
Clinical Test ◽  
Older Children ◽  
Spatial Release ◽  
Hearing Devices ◽  
Release From Masking ◽  
Test Retest Reliability

Pure-tone threshold audiometry is currently the standard test of hearing. However, in everyday life, we are more concerned with listening to speech of moderate loudness and, specifically, listening to a particular talker against a background of other talkers. FreeHear delivers strings of three spoken digits (0–9, not 7) against a background babble via three loudspeakers placed in front and to either side of a listener. FreeHear is designed as a rapid, quantitative initial assessment of hearing using an adaptive algorithm. It is designed especially for children and for testing listeners who are using hearing devices. In this first report on FreeHear, we present developmental considerations and protocols and results of testing 100 children (4–13 years old) and 23 adults (18–30 years old). Two of the six 4 year olds and 91% of all older children completed full testing. Speech reception threshold (SRT) for digits and noise colocated at 0° or separated by 90° both improved linearly across 4 to 12 years old by 6 to 7 dB, with a further 2 dB improvement for the adults. These data suggested full maturation at approximately 15 years old SRTs at 90° digits/noise separation were better by approximately 6 dB than SRTs colocated at 0°. This spatial release from masking did not change significantly across age. Test–retest reliability was similar for children and adults (standard deviation of 2.05–2.91 dB SRT), with a mean practice improvement of 0.04–0.98 dB. FreeHear shows promise as a clinical test for both children and adults. Further trials in people with hearing impairment are ongoing.

scholarly journals Spatial Release from Masking Using Clinical Corpora: Sentence Recognition in a Colocated or Spatially Separated Speech Masker

2020 ◽  
Vol 31 (04) ◽  
pp. 271-276
Author(s):  
Grant King ◽  
Nicole E. Corbin ◽  
Lori J. Leibold ◽  
Emily Buss
Keyword(s):  
Hearing Loss ◽  
Speech Recognition ◽  
Spatial Separation ◽  
Speech Corpus ◽  
Sentence Recognition ◽  
Spatial Release ◽  
The Mean ◽  
Release From Masking ◽  
Perceived Spatial Separation ◽  
Separation Conditions

Abstract Background Speech recognition in complex multisource environments is challenging, particularly for listeners with hearing loss. One source of difficulty is the reduced ability of listeners with hearing loss to benefit from spatial separation of the target and masker, an effect called spatial release from masking (SRM). Despite the prevalence of complex multisource environments in everyday life, SRM is not routinely evaluated in the audiology clinic. Purpose The purpose of this study was to demonstrate the feasibility of assessing SRM in adults using widely available tests of speech-in-speech recognition that can be conducted using standard clinical equipment. Research Design Participants were 22 young adults with normal hearing. The task was masked sentence recognition, using each of five clinically available corpora with speech maskers. The target always sounded like it originated from directly in front of the listener, and the masker either sounded like it originated from the front (colocated with the target) or from the side (separated from the target). In the real spatial manipulation conditions, source location was manipulated by routing the target and masker to either a single speaker or to two speakers: one directly in front of the participant, and one mounted in an adjacent corner, 90° to the right. In the perceived spatial separation conditions, the target and masker were presented from both speakers with delays that made them sound as if they were either colocated or separated. Results With real spatial manipulations, the mean SRM ranged from 7.1 to 11.4 dB, depending on the speech corpus. With perceived spatial manipulations, the mean SRM ranged from 1.8 to 3.1 dB. Whereas real separation improves the signal-to-noise ratio in the ear contralateral to the masker, SRM in the perceived spatial separation conditions is based solely on interaural timing cues. Conclusions The finding of robust SRM with widely available speech corpora supports the feasibility of measuring this important aspect of hearing in the audiology clinic. The finding of a small but significant SRM in the perceived spatial separation conditions suggests that modified materials could be used to evaluate the use of interaural timing cues specifically.

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