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Effective Masking Levels for Bone Conduction Auditory Brainstem Response Stimuli in Infants and Adults with Normal Hearing.
Ear Hear. 2020 09 10; 42(2):443-455.EH

Abstract

OBJECTIVE

The purpose of the present study was to investigate effective masking levels (EMLs) for bone conduction (BC) auditory brainstem response (ABR) testing in infants and adults. Early hearing detection and intervention programs aim to limit delays in identifying ear-specific type/degree of hearing loss in infants using the ABR. Ear-specific assessment poses challenges as sound delivered to one ear can travel across the skull and activate the contralateral cochlea. Wave V amplitude and latency measures ipsilateral and contralateral to the bone oscillator can be compared to isolate the test cochlea in some cases; however, when these findings are equivocal, clinical masking is required. This study aims to determine EMLs for ABRs elicited to 500- and 2000-Hz BC stimuli for normal-hearing infants (0 to 18 months) and adults.

DESIGN

Participants were 21 adults (18 to 54 years) and 24 infants (5 to 47 weeks) with normal hearing. BC 500- and 2000-Hz brief tonal stimuli at intensities approximating normal levels were presented via a B-71 oscillator (infants: 20 dB nHL at 500 Hz and 30 dB nHL at 2000 Hz; adults: 500 and 2000 Hz at 20 and 30 dB nHL, respectively). White noise masking was presented binaurally via ER-3A earphones (22 to 82 dB SPL; 10-dB steps). The lowest level of masking to eliminate a BC response was deemed the EML.

RESULTS

For stimuli presented at 20 dB nHL, adult mean (1 SD) EMLs for 500 and 2000 Hz were 65 (9) and 53 (6) dB SPL, respectively. Mean EMLs for infants were 80 (6) dB SPL for 500 Hz at 20 dB nHL and 64 (9) dB SPL for 2000 Hz at 30 dB nHL. Compared to adults, infants required approximately 13 dB more masking at 500 Hz but a similar amount of masking at 2000 Hz. Infants required 26 dB more masking at 500 versus 2000 Hz, whereas, adults required only 12 dB more masking.

CONCLUSIONS

Maximum binaural EMLs for infant BC responses elicited to 500 Hz at 20 dB nHL are 82 dB SPL, and for 2000 Hz at 30 and 40 dB nHL, respectively, are 72 and 82 dB SPL. Monaural masking levels for the nontest ear (assuming 10 dB of interaural attenuation) recommended clinically are as follows: (1) 500 Hz: 72 and 82 dB SPL at 20 and 30 dB nHL, respectively; and (2) 2000 Hz: 62, 72, and 82 dB SPL at 30, 40, and 50 dB nHL, respectively. Unsafe levels of white noise would be needed to effectively mask at greater stimulus levels.

Authors+Show Affiliations

School of Audiology and Speech Sciences, The University of British Columbia, Vancouver, British Columbia, Canada.No affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

32925305

Citation

Lau, Ricky, and Susan A. Small. "Effective Masking Levels for Bone Conduction Auditory Brainstem Response Stimuli in Infants and Adults With Normal Hearing." Ear and Hearing, vol. 42, no. 2, 2020, pp. 443-455.
Lau R, Small SA. Effective Masking Levels for Bone Conduction Auditory Brainstem Response Stimuli in Infants and Adults with Normal Hearing. Ear Hear. 2020;42(2):443-455.
Lau, R., & Small, S. A. (2020). Effective Masking Levels for Bone Conduction Auditory Brainstem Response Stimuli in Infants and Adults with Normal Hearing. Ear and Hearing, 42(2), 443-455. https://doi.org/10.1097/AUD.0000000000000947
Lau R, Small SA. Effective Masking Levels for Bone Conduction Auditory Brainstem Response Stimuli in Infants and Adults With Normal Hearing. Ear Hear. 2020 09 10;42(2):443-455. PubMed PMID: 32925305.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effective Masking Levels for Bone Conduction Auditory Brainstem Response Stimuli in Infants and Adults with Normal Hearing. AU - Lau,Ricky, AU - Small,Susan A, Y1 - 2020/09/10/ PY - 2020/9/15/pubmed PY - 2021/7/9/medline PY - 2020/9/14/entrez SP - 443 EP - 455 JF - Ear and hearing JO - Ear Hear VL - 42 IS - 2 N2 - OBJECTIVE: The purpose of the present study was to investigate effective masking levels (EMLs) for bone conduction (BC) auditory brainstem response (ABR) testing in infants and adults. Early hearing detection and intervention programs aim to limit delays in identifying ear-specific type/degree of hearing loss in infants using the ABR. Ear-specific assessment poses challenges as sound delivered to one ear can travel across the skull and activate the contralateral cochlea. Wave V amplitude and latency measures ipsilateral and contralateral to the bone oscillator can be compared to isolate the test cochlea in some cases; however, when these findings are equivocal, clinical masking is required. This study aims to determine EMLs for ABRs elicited to 500- and 2000-Hz BC stimuli for normal-hearing infants (0 to 18 months) and adults. DESIGN: Participants were 21 adults (18 to 54 years) and 24 infants (5 to 47 weeks) with normal hearing. BC 500- and 2000-Hz brief tonal stimuli at intensities approximating normal levels were presented via a B-71 oscillator (infants: 20 dB nHL at 500 Hz and 30 dB nHL at 2000 Hz; adults: 500 and 2000 Hz at 20 and 30 dB nHL, respectively). White noise masking was presented binaurally via ER-3A earphones (22 to 82 dB SPL; 10-dB steps). The lowest level of masking to eliminate a BC response was deemed the EML. RESULTS: For stimuli presented at 20 dB nHL, adult mean (1 SD) EMLs for 500 and 2000 Hz were 65 (9) and 53 (6) dB SPL, respectively. Mean EMLs for infants were 80 (6) dB SPL for 500 Hz at 20 dB nHL and 64 (9) dB SPL for 2000 Hz at 30 dB nHL. Compared to adults, infants required approximately 13 dB more masking at 500 Hz but a similar amount of masking at 2000 Hz. Infants required 26 dB more masking at 500 versus 2000 Hz, whereas, adults required only 12 dB more masking. CONCLUSIONS: Maximum binaural EMLs for infant BC responses elicited to 500 Hz at 20 dB nHL are 82 dB SPL, and for 2000 Hz at 30 and 40 dB nHL, respectively, are 72 and 82 dB SPL. Monaural masking levels for the nontest ear (assuming 10 dB of interaural attenuation) recommended clinically are as follows: (1) 500 Hz: 72 and 82 dB SPL at 20 and 30 dB nHL, respectively; and (2) 2000 Hz: 62, 72, and 82 dB SPL at 30, 40, and 50 dB nHL, respectively. Unsafe levels of white noise would be needed to effectively mask at greater stimulus levels. SN - 1538-4667 UR - https://www.unboundmedicine.com/medline/citation/32925305/Effective_Masking_Levels_for_Bone_Conduction_Auditory_Brainstem_Response_Stimuli_in_Infants_and_Adults_with_Normal_Hearing_ L2 - https://doi.org/10.1097/AUD.0000000000000947 DB - PRIME DP - Unbound Medicine ER -