J Am Acad Audiol 2019; 30(03): 187-197
DOI: 10.3766/jaaa.17067
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Benefits of Compression Amplification in Telephone Bluetooth-Assistive Listening Devices for People with Hearing Loss

Ching-Hsing Luo
*   Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan
†   School of Data and Computer Science, Sun Yat-Sen University, Guangzhou, China
Hung-Yue Chang
*   Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan
Tun-Shin Lo
‡   School of Speech Language Pathology and Audiology, Chung Shan Medical University, Taichung, Taiwan
§   Department of Otolaryngology, Chung Shan Medical University Hospital, Taichung, Taiwan
Cheng-Chi Tai
*   Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan
› Author Affiliations
Further Information

Publication History

Publication Date:
26 May 2020 (online)



Telephone conversation is one of the main scenarios where people with hearing loss require assistive listening devices (ALDs). Such people experience the greatest degree of difficulty during phone conversations in noisy environments.


This study compared the benefits of a linear scheme with a compression amplification scheme fitted with a prescription for sloping-type hearing loss implemented in a Bluetooth ALD in quiet and noisy environments.

Research Design:

Word recognition scores (WRSs) for the Mandarin monosyllable recognition test (MMRT) and participants’ satisfaction ratings were measured to serve as objective and subjective results, respectively.

Study Sample:

Twelve native Mandarin speakers aged 27–68 yr with mild to moderate sensorineural hearing loss participated in this study.


A compression amplification scheme with a prescription in maximizing speech intelligibility for sloping-type hearing loss was implemented in a Bluetooth ALD.

Data Collection and Analysis:

The MMRT WRSs of participants wearing the Bluetooth ALD were collected. Each test was conducted in a soundproof booth under quiet and 65-dBA speech noise environments. Each participant completed a satisfaction questionnaire administered by an audiologist. The collected WRSs were examined using analyses of variance and the satisfaction ratings were analyzed using Wilcoxon signed rank tests.


The mean MMRT WRSs of the compression amplification scheme were significantly higher than those of the linear scheme (57% and 53% higher in quiet and noisy environments, respectively). The mean satisfaction ratings of both schemes were between neutral and satisfied in the quiet environment, whereas in the noisy environment, the participants were more satisfied with the compression scheme than the linear scheme.


The results demonstrate the effective benefits of the compression amplification scheme fitted with a prescription in maximizing speech intelligibility for sloping-type hearing loss implemented in a Bluetooth ALD for people with mild to moderate hearing loss.

Funding of this study was provided by Merry Electronics, Inc.

This paper was presented at the Ninth Asia Pacific Conference on Speech, Language and Hearing in Taichung, Taiwan, on October 31, 2013.


  • 3GPP. Speech and Video Telephony Terminal Acoustic Test Specification, 3GPP TS 26.132 V6.0.0 (2004-09)
  • Alcántara JL, Moore BCJ, Kühnel V, Launer S. 2003; Evaluation of the noise reduction system in a commercial digital hearing aid. Int J Audiol 42 (01) 34-42
  • American National Standard Institution (ANSI). (2004) Specification for Audiometers. ANSI S3.6. New York, NY: ANSI.
  • Blamey PJ. 2005; Adaptive dynamic range optimization (ADRO): a digital amplification strategy for hearing aids and cochlear implants. Trends Amplif 9 (02) 77-98
  • Chang H-Y, Luo C-H, Lo T-S, Chen HC, Huang KY, Liao WH, Su MC, Liu SY, Wang NM. 2017; Benefits of incorporating the adaptive dynamic range optimization amplification scheme into an assistive listening device for people with mild or moderate hearing loss. Assist Technol 1-7
  • Chia EM, Wang JJ, Rochtchina E, Cumming RR, Newall P, Mitchell P. 2007; Hearing impairment and health-related quality of life: the Blue Mountains Hearing Study. Ear Hear 28 (02) 187-195
  • Dillon H. 2001. Hearing Aids. Sydney: Boomerang Press; 72-73
  • Dobie RA. 2007; Noise-induced permanent threshold shifts in the occupational noise and hearing survey: an explanation for elevated risk estimates. Ear Hear 28 (04) 580-591
  • Dynamic Hearing 2008 ATLAS Information Sheet—ALTAS VoiceField for CSR BlueCore Multimedia. http://www.dynamichearing.com.au . Accessed October 1, 2008
  • Hartley D, Rochtchina E, Newall P, Golding M, Mitchell P. 2010; Use of hearing AIDS and assistive listening devices in an older Australian population. J Am Acad Audiol 21 (10) 642-653
  • Hawkins DB, Schum DJ. 1985; Some effects of FM-system coupling on hearing aid characteristics. J Speech Hear Disord 50 (02) 132-141
  • Hickson LM. 1994; Compression amplification in hearing aids. Am J Audiol 3 (03) 51-65
  • International Telecommunication Union (ITU) 1999. Artificial Voices. ITU-T Recommendation; 50
  • International Telecommunication Union (ITU) 2011. Transmission Characteristics for Wideband Digital Loudspeaking and Hands-Free Telephony Terminals. ITU-T Recommendation; 341
  • Jabra 2017 TALK. http://www.jabra.com/bluetooth-headsets/jabra-talk . Accessed April 25, 2017.
  • Kepler LJ, Terry M, Sweetman RH. 1992; Telephone usage in the hearing-impaired population. Ear Hear 13 (05) 311-319
  • Le Bouquin R. 1996; Enhancement of noisy speech signals: application to mobile radio communications. Speech Commun 18 (01) 3-19
  • Martin L, Blamey P, James C, Galvin K, Macfarlane D. 2001; Adaptive dynamic range optimisation of hearing aids. Acoust Aust 29 (01) 21-24
  • McFerran DJ, Baguley DM. 2007; Acoustic shock. J Laryngol Otol 121 (04) 301-305
  • Meyer J, Simmer KU. 1997 Multi-channel speech enhancement in a car environment using Wiener filtering and spectral subtraction. Paper presented at the Proc IEEE Int Conf Acoust Speech Signal Process
  • Munro KJ, Davis J. 2003; Deriving the real-ear SPL of audiometric data using the “coupler to dial difference” and the “real ear to coupler difference”. Ear Hear 24 (02) 100-110
  • Pagano M, Gauvreau K. 2000. Principles of Biostatistics. Vol. 2 Pacific Grove, CA: Duxbury Press;
  • Qian H, Loizou PC, Dorman MF. 2003; A phone-assistive device based on Bluetooth technology for cochlear implant users. IEEE Trans Neural Syst Rehabil Eng 11 (03) 282-287
  • Skinner MW, Miller JD. 1983; Amplification bandwidth and intelligibility of speech in quiet and noise for listeners with sensorineural hearing loss. Audiology 22 (03) 253-279
  • Sound ID 2007 SM100 User Manual. http://www.soundid.com/pdf/manuals/SM100_User_Manual.pdf . Accessed October 1, 2013
  • Sound World Solutions (SWS) 2015 Sound World Solutions CS50 Plus User Guide. http://www.soundworldsolutions.com/downloads/user-guides/sound-world-solutions-cs50-plus-user-guide-english.pdf . Accessed December 3, 2017
  • Starkey Hearing Technology (SHT) 2016 Halo, Made for iPhone Hearing Aids. http://www.starkey.com/hearing-aids/technologies/halo-wireless-hearing-aids . Accessed April 1, 2016
  • Tsai K-S, Tseng L-H, Wu C-J, Young S-T. 2009; Development of a mandarin monosyllable recognition test. Ear Hear 30 (01) 90-99
  • Wang L, Su F. 1979; Development of phonemically balanced monosyllabic Mandarin word lists. J Otolaryngol Soc Taiwan 14: 1-9
  • Wise C, Dickson B, Blamey P. 2006; Adaptive range optimisation for telephony. Acoust Aust 34 (03) 117-121
  • Zakis JA, Wise C. 2007; The acoustic and perceptual effects of two noise-suppression algorithms. J Acoust Soc Am 121 (01) 433-441