Trends in Amplification Volume 10 Number 2 June 2006 65-66 © 2006 Sage Publications 10.1177/1084713806289552 http://tia.sagepub.com hosted at http://online.sagepub.com
From the Editor
B
oth new and experienced hearing aid users complain that their hearing aids amplify noise. New hearing aid users are accustomed to the unnaturally quiet world caused by hearing loss and are assaulted by the amplification of sounds that they may have even forgotten exist. Experienced hearing aid users can be frustrated by trying to separate the signal that they want to hear from competing signals that are also amplified. Over the years, the hearing industry has attempted to address the complaints of hearing aid users by developing various methods of noise reduction in their hearing aids. The processing in digital hearing aids is much more complicated than that in analog hearing aids, and the approaches to noisereduction processing in current hearing aids are very different from those in the past. To further complicate matters, digital noise reduction (DNR) algorithms are used in combination with other types of technology and processing that may also affect the perception of background noise, including directional microphones, feedback cancellation, expansion, and multiband compression. The proprietary nature of the DNR algorithms often makes it difficult for the clinician to understand how the hearing aid will work to meet the needs of a particular client. The present issue of Trends in Amplification provides information about how DNR algorithms work, how to determine noise reduction effects, and the perceptual consequences of DNR for several specific hearing aids. In the first article, Bentler and Chiou provide an overview of current approaches to DNR processing in hearing aids and present interesting data showing that differences in DNR algorithms result in differences in hearing aid output. The second and third articles of this issue contain reports evaluating performance with 2 different DNR hearing aids. The article by Mueller and colleagues reveals that although speech intelligibility was not affected by the DNR hearing aid they evaluated, acceptable noise level with DNR on was significantly higher than with DNR off. This finding implies that this type of DNR may increase the acceptability of the hearing aid and provide greater user comfort.
The final article by Palmer and colleagues reports an investigation of how noise annoyance and aversiveness are affected by a hearing aid (with and without DNR). They compared ratings of noise annoyance and aversiveness by hearing aid users with and without amplification (DNR off and DNR on) to the perception of noise by persons with normal hearing. Amplification was found to increase both noise annoyance and aversiveness ratings, whether DNR was active or inactive. With amplification, perception of noise was similar to that of listeners with normal hearing. The technique of comparing perception of noise with the hearing aid to perception of normal listeners is an interesting one. Gathering this type of information on different hearing aids and sharing this type of information with prospective hearing aid users may help them develop realistic expectations for amplified sound.
About the Authors Ruth Bentler is a professor in the Department of Speech Pathology and Audiology at the University of Iowa, Iowa City, Iowa, where she obtained her PhD in 1987. Her research has focused primarily on efficacy and effectiveness of signal processing and fitting schemes for adult hearing-impaired hearing aid users. In the past 5 years, she has focused on DNR, directional microphone, and feedback cancellation features of the currently marketed digital signal processing hearing aids. She has published her findings and presented her research at the major audiology, hearing aid, and hearing research meetings. Li-Kuei Chiou is an AuD/PhD student in the Department of Speech Pathology and Audiology at the University of Iowa, Iowa City, Iowa. Her undergraduate degree is from National University in Taiwan. Her research focus has been in hearing aids, with application to the pediatric population. Benjamin W. Y. Hornsby is a research assistant professor in the Department of Hearing and Speech Science at Vanderbilt University, Nashville, Tennessee, and is a senior editor of Trends in Amplification. He 65
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Trends in Amplification / Vol. 10, No. 2, June 2006
has published research reporting investigations of both subject-specific and environment-specific factors that affect the communicative and speech-understanding abilities of persons with hearing loss. In recent research, he has focused on the evaluation of different hearing aid signal-processing techniques on speech understanding and listening comfort. H. Gustav Mueller is professor of audiology at Vanderbilt University, Nashville, Tennessee, a consultant to Siemens Hearing Instruments, and contributing editor of The Hearing Journal. Dr Mueller is one of the founders of the American Academy of Audiology and an internationally known workshop lecturer. He has published more than 150 articles and book chapters on diagnostic audiology and hearing aid applications. He is the senior author of the books Communication Disorders in Aging and Probe Microphone Measurements and is a coauthor of The Audiologists’ Desk Reference, Volumes I and II. Catherine V. Palmer obtained her master’s degree and PhD at Northwestern University, Evanston, Illinois. She is an associate professor in the Department
of Communication Science and Disorders at the University of Pittsburgh, Pittsburgh, Pennsylvania, and serves as the director of audiology and hearing aids at the University of Pittsburgh Medical Center. Dr Palmer’s research focuses on learning in the adult auditory system and matching technology to individual needs. She has published extensively in the area of hearing aids. Jennifer Weber is an associate professor and assistant program area coordinator of audiology and speech-language sciences at the University of Northern Colorado, Greeley, Colorado. She also serves as the clinical coordinator of audiology services for the University of Northern Colorado Audiology and Speech-Language Pathology Clinic. Dr Weber teaches undergraduate and graduate courses in diagnostic and pediatric audiology and amplification. Her research interests include aural rehabilitation, hearing aids, and diagnostic audiology.
Downloaded from tia.sagepub.com at INDIANA UNIV on May 10, 2015
Arlene C. Neuman Editor-in-Chief
From the Editor
B
oth new and experienced hearing aid users complain that their hearing aids amplify noise. New hearing aid users are accustomed to the unnaturally quiet world caused by hearing loss and are assaulted by the amplification of sounds that they may have even forgotten exist. Experienced hearing aid users can be frustrated by trying to separate the signal that they want to hear from competing signals that are also amplified. Over the years, the hearing industry has attempted to address the complaints of hearing aid users by developing various methods of noise reduction in their hearing aids. The processing in digital hearing aids is much more complicated than that in analog hearing aids, and the approaches to noisereduction processing in current hearing aids are very different from those in the past. To further complicate matters, digital noise reduction (DNR) algorithms are used in combination with other types of technology and processing that may also affect the perception of background noise, including directional microphones, feedback cancellation, expansion, and multiband compression. The proprietary nature of the DNR algorithms often makes it difficult for the clinician to understand how the hearing aid will work to meet the needs of a particular client. The present issue of Trends in Amplification provides information about how DNR algorithms work, how to determine noise reduction effects, and the perceptual consequences of DNR for several specific hearing aids. In the first article, Bentler and Chiou provide an overview of current approaches to DNR processing in hearing aids and present interesting data showing that differences in DNR algorithms result in differences in hearing aid output. The second and third articles of this issue contain reports evaluating performance with 2 different DNR hearing aids. The article by Mueller and colleagues reveals that although speech intelligibility was not affected by the DNR hearing aid they evaluated, acceptable noise level with DNR on was significantly higher than with DNR off. This finding implies that this type of DNR may increase the acceptability of the hearing aid and provide greater user comfort.
The final article by Palmer and colleagues reports an investigation of how noise annoyance and aversiveness are affected by a hearing aid (with and without DNR). They compared ratings of noise annoyance and aversiveness by hearing aid users with and without amplification (DNR off and DNR on) to the perception of noise by persons with normal hearing. Amplification was found to increase both noise annoyance and aversiveness ratings, whether DNR was active or inactive. With amplification, perception of noise was similar to that of listeners with normal hearing. The technique of comparing perception of noise with the hearing aid to perception of normal listeners is an interesting one. Gathering this type of information on different hearing aids and sharing this type of information with prospective hearing aid users may help them develop realistic expectations for amplified sound.
About the Authors Ruth Bentler is a professor in the Department of Speech Pathology and Audiology at the University of Iowa, Iowa City, Iowa, where she obtained her PhD in 1987. Her research has focused primarily on efficacy and effectiveness of signal processing and fitting schemes for adult hearing-impaired hearing aid users. In the past 5 years, she has focused on DNR, directional microphone, and feedback cancellation features of the currently marketed digital signal processing hearing aids. She has published her findings and presented her research at the major audiology, hearing aid, and hearing research meetings. Li-Kuei Chiou is an AuD/PhD student in the Department of Speech Pathology and Audiology at the University of Iowa, Iowa City, Iowa. Her undergraduate degree is from National University in Taiwan. Her research focus has been in hearing aids, with application to the pediatric population. Benjamin W. Y. Hornsby is a research assistant professor in the Department of Hearing and Speech Science at Vanderbilt University, Nashville, Tennessee, and is a senior editor of Trends in Amplification. He 65
Downloaded from tia.sagepub.com at INDIANA UNIV on May 10, 2015
66
Trends in Amplification / Vol. 10, No. 2, June 2006
has published research reporting investigations of both subject-specific and environment-specific factors that affect the communicative and speech-understanding abilities of persons with hearing loss. In recent research, he has focused on the evaluation of different hearing aid signal-processing techniques on speech understanding and listening comfort. H. Gustav Mueller is professor of audiology at Vanderbilt University, Nashville, Tennessee, a consultant to Siemens Hearing Instruments, and contributing editor of The Hearing Journal. Dr Mueller is one of the founders of the American Academy of Audiology and an internationally known workshop lecturer. He has published more than 150 articles and book chapters on diagnostic audiology and hearing aid applications. He is the senior author of the books Communication Disorders in Aging and Probe Microphone Measurements and is a coauthor of The Audiologists’ Desk Reference, Volumes I and II. Catherine V. Palmer obtained her master’s degree and PhD at Northwestern University, Evanston, Illinois. She is an associate professor in the Department
of Communication Science and Disorders at the University of Pittsburgh, Pittsburgh, Pennsylvania, and serves as the director of audiology and hearing aids at the University of Pittsburgh Medical Center. Dr Palmer’s research focuses on learning in the adult auditory system and matching technology to individual needs. She has published extensively in the area of hearing aids. Jennifer Weber is an associate professor and assistant program area coordinator of audiology and speech-language sciences at the University of Northern Colorado, Greeley, Colorado. She also serves as the clinical coordinator of audiology services for the University of Northern Colorado Audiology and Speech-Language Pathology Clinic. Dr Weber teaches undergraduate and graduate courses in diagnostic and pediatric audiology and amplification. Her research interests include aural rehabilitation, hearing aids, and diagnostic audiology.
Downloaded from tia.sagepub.com at INDIANA UNIV on May 10, 2015
Arlene C. Neuman Editor-in-Chief
