Introducing real-life listening features into the clinical test environment: Part II: Measuring the hearing performance and evaluating the listening effort of individuals with a hearing implant

Objectives: The controlled clinical test environment is very different from real-life listening situations, where the presence of additional speakers and variations in background noise signals can affect listening performances. The primary objective of this study is to reduce the gap between clinical results and real-life performances that are reported for many hearing implant users.

Methods: Similar to Part I of this study, hearing performance and sound perception are evaluated using the following tests: (i) the Roving Level Test, (ii) the Just Understanding Speech Test, (iii) the Performance Perceptual Test, (iv) the Visual Analogue Scale to evaluate the perceived listening effort required for a range of background noise levels, and (v) the Hearing Implant Sound Quality questionnaire. All subjects recruited for this study used MED-EL hearing implant systems.

Results: Results show that, similar to normal hearing listeners, hearing implant users tend to accurately estimate their hearing abilities, and both listening effort and speech recognition thresholds tend to increase with increasing noise.

Discussion: The proposed test battery for evaluating speech understanding and listening effort were suitable for use in this study as all of the implant users were able to complete the tests. This test battery can be used to provide audiologists with further information relating to real-life listening performances.

Conclusion: Evaluating the self-estimated and verified performance measurements of hearing implant users in real-life listening situations are essential for providing information regarding the discrepancies observed between the objective and subjective reports of hearing difficulties.     

Effects of signal bandwidth on listening effort in young- and middle-aged adults

Objective: The purpose of this study was to assess the effects of signal bandwidth, noise and signal predictability on listening effort among younger and middle-aged individuals with normal hearing, where YNH?=?young normal hearing and ONH?=?older normal hearing. It was of interest to determine if a reduction in high-frequency energy would differentially influence performance between the two groups.

Design: A mixed-model design was used, where listening effort, word identification and effort ratings served as the within-subject factors and listener group served as the between-subject factor.

Study sample: Twenty listeners aged 18–25 years (YNH group) and 20 listeners aged 40–55 years (ONH group) participated in the experiment.

Results: Results showed significantly poorer word recall and significantly higher perceived effort among the ONH group. Increasing the signal bandwidth from 2?to 8?kHz significantly improved word recall and decreased listening effort ratings. Effort ratings from both groups matched word recall performance in that when word recall was lower perceived effort was higher and when word recall was higher perceived effort was lower.

Conclusions: In general, providing additional high-frequency energy up to 8?kHz reduced listening effort among both groups of listeners. However, the ONH group, experienced additional effort when completing the tasks.     

Measuring listening effort expended by adolescents and young adults with unilateral or bilateral cochlear implants or normal hearing

Abstract

Objectives

To compare the listening effort expended by adolescents and young adults using implants versus their peers with normal hearing when these two groups are achieving similar speech perception scores. The study also aimed to compare listening effort expended by adolescents and young adults with bilateral cochlear implants when using two implants versus one.

Methods

Eight participants with bilateral cochlear implants and eight with normal hearing aged 10–22 years were included. Using a dual-task paradigm, participants repeated consonant–nucleus–consonant (CNC) words presented in noise and performed a visual matching task. Signal-to-noise ratios were set individually to ensure the word perception task was challenging but manageable for all. Reduced performance on the visual task in the dual-task condition relative to the single-task condition was indicative of the effort expended on the listening task.

Results

The cochlear implant group, when using bilateral implants, expended similar levels of listening effort to the normal hearing group when the two groups were achieving similar speech perception scores. For three individuals with cochlear implants, and the group, listening effort was significantly reduced with bilateral compared to unilateral implants.

Discussion

The similar amount of listening effort expended by the two groups indicated that a higher signal-to-noise ratio overcame limitations in the auditory information received or processed by the participants with implants. This study is the first to objectively compare listening effort using two versus one cochlear implant. The results provide objective evidence that reduced listening effort is a benefit that some individuals gain from bilateral cochlear implants.     

Subjective evaluation of single microphone noise reduction with different time constants

Abstract

Objective: Previous studies on single microphone noise reduction (NR) in hearing aids (HAs) have shown that some NR algorithms provide beneficial effects in terms of listener preference. To improve HA user satisfaction, we are interested in characteristics that determine preferences for NR, and in the inter-individual variability. The aim of this study was to test if dynamic properties of NR influence listener preference.

Design: The gain reduction at speech offsets of a NR algorithm was slowed down by applying temporal exponential smoothing. At speech onsets the gain recovery was left unchanged. Test signals consisted of speech in continuous and modulated speech-shaped background noise, processed with three time constants: 0, 100, and 200?ms.

Study sample: 16 Normal hearing (NH) and 16 hearing impaired (HI) subjects participated in a paired-comparison listening test.

Results: NH subjects as a group had a significant preference for NR with time constants of 100, or 200?ms (slower acting NR). HI listeners as a group preferred NR over no NR, but had no clear preference for fast or slow NR. Patterns of preference differed between individual listeners.

Conclusions: NR dynamics had an impact on individual listener preference and should be considered when optimising HAs.     

Wireless binaural hearing aid technology for telephone use and listening in wind noise

Objective: To assess the speech perception benefits of binaural streaming technology for bilateral hearing aid users in two difficult listening conditions.

Design: Two studies were conducted to compare hearing aid processing features relating to telephone use and wind noise. Speech perception testing was conducted in four different experimental conditions in each study.

Study sample: Ten bilaterally-aided children in each study.

Results: Significant improvements in speech perception were obtained with a wireless feature for telephone use. Significant speech perception benefits were also obtained with wireless hearing aid features when listening to speech in simulated wind noise.

Conclusions: Binaural signal processing algorithms can significantly improve speech perception for bilateral hearing aid users in challenging listening situations.     

Effects of noise and reverberation on speech recognition with variants of a multichannel adaptive dynamic range compression scheme

Abstract

Objective: Adaptive compression methods in hearing aids have been developed to maximise audibility while preserving temporal envelope modulations. Increasing the number of channels may improve listening comfort for loud sounds. However, the effects of this on speech recognition in different environmental conditions are unknown. This study evaluated the effects of different channel architectures and adaptive compression properties on speech recognition in noise and reverberation.

Design: Sentences were mixed with steady or modulated noise at three signal-to-noise ratios (SNRs). These were processed with and without reverberation and amplified with four proprietary adaptive compression methods or linear amplification.

Study sample: 36 listeners with mild to moderately-severe hearing loss.

Results: Adaptive compression improved speech recognition over linear amplification to a small extent, with no significant differences among methods using 4 or 24 channels or a combination thereof. These effects remained across the different background noise and reverberation conditions.

Conclusions: Increasing the number of channels does not negatively affect speech recognition in noise and reverberation when adaptive compression is used. If future research shows that increasing the number of channels improves listening comfort for loud sounds, these results indicate that adaptive compression methods with as many as 24 channels are viable options for hearing aids.     

Evaluation of the preliminary auditory profile test battery in an international multi-centre study

Abstract

Objective: This paper describes the composition and international multi-centre evaluation of a battery of tests termed the preliminary auditory profile. It includes measures of loudness perception, listening effort, speech perception, spectral and temporal resolution, spatial hearing, self-reported disability and handicap, and cognition. Clinical applicability and comparability across different centres are investigated. Design: Headphone tests were conducted in five centres divided over four countries. Effects of test-retest, ear, and centre were investigated. Results for normally-hearing (NH) and hearing-impaired (HI) listeners are presented. Study sample: Thirty NH listeners aged 19–39 years, and 72 HI listeners aged 22–91 years with a broad range of hearing losses were included. Results: Test-retest reliability was generally good and there were very few right/left ear effects. Results of all tests were comparable across centres for NH listeners after baseline correction to account for necessary differences between test materials. For HI listeners, results were comparable across centres for the language-independent tests. Conclusions: The auditory profile forms a clinical test battery that is applicable in four different languages. Even after baseline correction, differences between test materials have to be taken into account when interpreting results of language-dependent tests in HI listeners.     

Headphone listening habits,hearing thresholds and listening levels in Swedish adolescents with severe to profound HL and adolescents with normal hearing

Abstract

Objective: Research has minimally focussed on the music listening habits and preferred sound volumes among adolescents with severe to profound congenital HL. Listening to music played at loud sound volumes and for a long duration of time could imply risks of worsening the HL. Therefore, it is important to investigate the listening habits in adolescents with HL. The aim of the present study was to describe the use of personal music devices, subjective estimated sound levels, measured sound levels, listening habits, and hearing symptoms in adolescents with severe to profound hearing loss compared with adolescents with normal hearing.

Design: The study was conducted in two steps. First, a questionnaire was given to students with or without hearing loss. In step two, hearing and sound level measurements were made in a subsample from both groups.

Study sample: The study sample were based on 112 seventeen-year-old students with severe to profound hearing loss and 279 adolescents with normal hearing. Hearing thresholds and listening levels was measured on two subsamples based on 29 adolescents with severe to profound hearing loss and 50 adolescents from the group with normal hearing.

Results: The results showed that adolescents with severe to profound hearing loss listened to significantly louder sound levels for longer periods. For both groups, those listening at louder sound levels had poorer hearing thresholds. This finding is especially alarming for subjects with hearing loss. Among those listening above 85?dB per occasion, the sound level ranged between 85.8?dB up to 109?dB for those with hearing loss, whereas the sound level ranged between 85.5?dB and 100?dB for those with normal hearing.

Conclusions: Adolescents with congenital hearing loss used portable music devices in the same manner as adolescents with normal hearing. However, adolescents with hearing loss listened to louder sound volumes most likely to compensate for their hearing loss, which significantly increases the risk of further damage to their hearing. From a hearing rehabilitation perspective it could be concluded that aspect of music listening habits should be focussed in order to prevent noise induced hearing loss among individuals with congenital hearing loss.     

Semantic context improves speech intelligibility and reduces listening effort for listeners with hearing impairment

Objective: We investigated whether speech intelligibility and listening effort for hearing-aid users is affected by semantic context and hearing-aid setting. Design: Participants heard target sentences spoken in a reverberant background of cafeteria noise and competing speech. Participants reported each sentence verbally. Eight participants also rated listening effort after each sentence. Sentence topic was either the same as, or different from, the previous target sentence. Study sample: Twenty participants with sensorineural hearing loss were fit binaurally with Signia receiver-in-the-canal hearing aids. Participants performed the task twice: once using the hearing aid’s omnidirectional setting and once using the “Reverberant Room” setting, designed to aid listening in reverberant environments. Results: Participants achieved better speech intelligibility for same-topic than different-topic sentences, and when they used the “Reverberant Room” than the omnidirectional hearing-aid setting. Participants who rated effort showed a reliable reduction in listening effort for same-topic sentences and for the “Reverberant Room” hearing-aid setting. The improvement in speech intelligibility from semantic context (i.e. same-topic compared to different-topic sentences) was greater than the improvement gained from changing hearing-aid setting. Conclusions: These findings highlight the enormous potential of cognitive (specifically, semantic) factors for improving speech intelligibility and reducing perceived listening effort in noise for hearing-aid users.     

The relationship between speech recognition,behavioural listening effort,and subjective ratings

Objective: The purpose of this study was to evaluate the reliability and validity of four subjective questions related to listening effort. A secondary purpose of this study was to evaluate the effects of hearing aid beamforming microphone arrays on word recognition and listening effort. Design: Participants answered subjective questions immediately following testing in a dual-task paradigm with three microphone settings in a moderately reverberant laboratory environment in two noise configurations. Participants rated their: (1) mental work, (2) desire to improve the situation, (3) tiredness, and (4) desire to give up. Data were analysed using repeated measures and reliability analyses. Study sample: Eighteen adults with symmetrical sensorineural hearing loss participated. Results: Beamforming differentially affected word recognition and listening effort. Analysis revealed the same pattern of results for behavioural listening effort and subjective ratings of desire to improve the situation. Conversely, ratings of work revealed the same pattern of results as word recognition performance. Ratings of tiredness and desire to give up were unaffected by hearing aid microphone or noise configuration. Conclusions: Participant ratings of their desire to control the listening situation appear to reliable subjective indicators of listening effort that align with results from a behavioural measure of listening effort.     

A systematic review and meta-analysis assessing the effectiveness of alternative listening devices to conventional hearing aids in adults with hearing loss

Abstract

Recent technological advances have led to a rapid increase in alternative listening devices to conventional hearing aids. The aim was to systematically review the existing evidence to assess the effectiveness of alternative listening devices in adults with mild and moderate hearing loss. A systematic search strategy of the scientific literature was employed, reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) checklist. Eleven studies met eligibility for inclusion: two studies evaluated personal sound amplification products, and nine studies assessed remote microphone systems (frequency modulation, Bluetooth, wireless). The evidence in this review suggests that alternative listening devices improve behavioural measures of speech intelligibility relative to unaided and/or aided conditions. Evidence for whether alternative listening devices improve self-reported outcomes is inconsistent. The evidence was judged to be of poor to good quality and subject to bias due to limitations in study design. Our overall recommendation is that high-quality evidence (i.e. randomised controlled trials) is required to demonstrate the effectiveness of alternative listening devices. Such evidence is not currently available and is necessary to guide healthcare commissioners and policymakers when considering new service delivery models for adults with hearing loss.

Review registration: Prospective Register of Systematic Reviews (PROSPERO), CRD42015029582     

Increasing motivation changes subjective reports of listening effort and choice of coping strategy

Abstract

Objective: The purpose of this project was to examine the effect of changing motivation on subjective ratings of listening effort and on the likelihood that a listener chooses either a controlling or an avoidance coping strategy. Design: Two experiments were conducted, one with auditory-only (AO) and one with auditory-visual (AV) stimuli, both using the same speech recognition in noise materials. Four signal-to-noise ratios (SNRs) were used, two in each experiment. The two SNRs targeted 80% and 50% correct performance. Motivation was manipulated by either having participants listen carefully to the speech (low motivation), or listen carefully to the speech and then answer quiz questions about the speech (high motivation). Study sample: Sixteen participants with normal hearing participated in each experiment. Eight randomly selected participants participated in both. Results: Using AO and AV stimuli, motivation generally increased subjective ratings of listening effort and tiredness. In addition, using auditory-visual stimuli, motivation generally increased listeners’ willingness to do something to improve the situation, and decreased their willingness to avoid the situation. Conclusions: These results suggest a listener's mental state may influence listening effort and choice of coping strategy.     

Preferred listening levels: the effect of background noise for moderate-to-profoundly hearing impaired aid users

The effects of background noise on the choice of preferred listening level for moderately-to-profoundly hearing impaired adults were investigated. During three listening conditions: 'quiet' (isolated monosyllables), 'suppress' (speech with noise attenuated in the gaps between words), and 'steady' (speech with continuous noise), subjects chose a level that maximized intelligibility without being uncomfortable while listening through a hearing aid. The group mean preferred level for 'suppress' was significantly higher than for 'steady', indicating that the level of noise between words influenced these subjects' choice of listening level. Average word recognition scores were higher in 'suppress' than in 'steady', but the difference was not statistically significant. Subjective loudness and quality ratings indicated no reduction in comfort or quality at the higher level for 'suppress'. The results suggest that a hearing aid that attenuated the level of background noise between words, or temporarily increased the gain during each word, would enable some listeners to tolerate higher levels of speech, thereby improving audibility and possibly speech perception while maintaining listening comfort.     

Investigating Speech Recognition and listening effort with different device configurations in adult cochlear implant users

Objectives: The purpose of this study was to investigate speech recognition in noise and listening effort among a group of adults with cochlear implants (CIs). Two main research questions were addressed. First, what are the effects of omni versus directional microphone configuration on speech recognition and listening effort for noisy conditions? Second, what is the effect of unilateral versus bimodal or bilateral CI listening on speech recognition and listening effort in noisy conditions?

Design: Sixteen adults (mean age 58 years) with CIs participated. Listening effort was measured using a dual-task paradigm and also using a self-reported rating of difficulty scale. In the dual-task measure, participants were asked to repeat monosyllabic words while at the same time press a button in response to a visual stimulus. Participants were tested in two baseline conditions (speech perception alone and visual task alone) and in the following experimental conditions: (1) quiet with an omnidirectional microphone, (2) noise with an omnidirectional microphone, (3) noise with a directional microphone, and (4) noise with a directional microphone and with a second sided CI or hearing aid. When present, the noise was fixed with a +5?dB signal-to-noise ratio. After each listening condition, the participants rated the degree of listening difficulty.

Results: Changing the microphone from omni to directional mode significantly enhanced speech recognition in noise performance. There were no significant changes in speech recognition between the unilateral and bimodal/bilateral CI listening conditions. Listening effort, as measured by reaction time, increased significantly between the baseline and omnidirectional quiet listening condition though did not change significantly across the remaining listening conditions. Self-perceived listening effort revealed a greater effort for the noisy conditions, and reduced effort with the move from an omni to a directional microphone.

Conclusions: Directional microphones significantly improve speech in noise recognition over omnidirectional microphones and allowed for decreased self-perceived listening effort. The dual task used in this study failed to show any differences in listening effort across the experimental conditions and may not be sensitive enough to detect changes in listening effort.     

How directional microphones affect speech recognition,listening effort and localisation for listeners with moderate-to-severe hearing loss

Objective: The purpose of this study was to evaluate the effects of directional microphone use on laboratory measures of sentence recognition, listening effort and localisation. An additional purpose of this study was to evaluate the effects of asymmetric directional microphone use on the same laboratory measures. Design: Three hearing aid conditions were evaluated: (1) bilateral omnidirectional microphones, (2) bilateral directional microphones and (3) asymmetric microphones (directional microphone for only one hearing aid). Sentence recognition performance was evaluated using a connected speech test. Listening effort was evaluated using a dual-task paradigm with a response time-based secondary task requiring word categorisation. Localisation was examined using a complex task requiring localisation and recall of speech originating from one of four loudspeakers in the horizontal plane (?60°, ?45°,?+45°,?+60°). Study sample: Eighteen adults (M?=?61.8 years) with symmetrical, moderate-to-severe hearing loss participated. Results: Performance on each task was analysed separately using a repeated measures analysis of variance. Results revealed directional benefits for sentence recognition and listening effort, but microphone setting did not affect localisation. Performance was equivalent with symmetric and asymmetric directional configurations. Conclusions: Bilateral and asymmetric directional microphone configurations equally improved sentence recognition and listening effort; neither affected localisation or recall.     

The performance of an automatic acoustic-based program classifier compared to hearing aid users’ manual selection of listening programs

Objective: To compare preference for and performance of manually selected programmes to an automatic sound classifier, the Phonak AutoSense OS. Design: A single blind repeated measures study. Participants were fit with Phonak Virto V90 ITE aids; preferences for different listening programmes were compared across four different sound scenarios (speech in: quiet, noise, loud noise and a car). Following a 4-week trial preferences were reassessed and the users preferred programme was compared to the automatic classifier for sound quality and hearing in noise (HINT test) using a 12 loudspeaker array. Study sample: Twenty-five participants with symmetrical moderate-severe sensorineural hearing loss. Results: Participant preferences of manual programme for scenarios varied considerably between and within sessions. A HINT Speech Reception Threshold (SRT) advantage was observed for the automatic classifier over participant’s manual selection for speech in quiet, loud noise and car noise. Sound quality ratings were similar for both manual and automatic selections. Conclusions: The use of a sound classifier is a viable alternative to manual programme selection.     

Perceived listening effort and speech intelligibility in reverberation and noise for hearing-impaired listeners

Objective: The purpose of this study was to assess perceived listening effort and speech intelligibility in reverberant and noisy conditions for hearing-impaired listeners for conditions that are similar according to the speech transmission index (STI). Design: Scaled listening effort was measured in four different conditions at five different STI generated using various relative contributions of noise and reverberant interferences. Intelligibility was measured for a subset of conditions. Study sample: Twenty mildly to moderately hearing-impaired listeners. Results: In general, listening effort decreased and speech intelligibility increased with increasing STI. For simulated impulse responses consisting of white Gaussian noise exponentially decaying in time, a good agreement between conditions of different relative contributions of noise and reverberation was found. For real impulse responses, the STI slightly overestimated the effect of reverberation on the perceived listening effort and underestimated its effect on speech intelligibility. Including the average hearing loss in the calculation of the STI led to a better agreement between STI predictions and subjective data. Conclusion: Speech intelligibility and listening effort provide complementary tools to evaluate speech perception over a broad range of acoustic scenarios. In addition, when incorporating hearing loss information the STI provides a rough prediction of listening effort in these acoustic scenarios.     

Daily music exposure dose and hearing problems using personal listening devices in adolescents and young adults: A systematic review

Objective: This systematic review aimed to explore the evidence on whether the preferred listening levels (PLLs) and durations of music listening through personal listening devices (PLDs) in adolescents and young adults exceed the current recommended 100% daily noise dose; together with the impact on hearing and possible influential factors of such listening behaviours. Design: A systematic search was conducted using multiple online bibliographic databases. Study sample: The 26 studies were included on the basis of the inclusion and exclusion criteria. Results: The results showed that up to 58.2% of participants exceeded the 100% daily noise dose, particularly in the presence of background noise. Significantly positive correlations were found among background noise levels and mean PLLs, as well as the proportion of participants exceeding the 100% daily noise dose. Moreover, significantly worse hearing thresholds were found in PLD users using audiometry, and significantly poor results in otoacoustic emission (OAE), even in the participants with self-reported ‘normal hearing’. Conclusion: It is crucial to develop appropriate standards and safe recommendations for daily music exposure dose in future studies. Providing an essential guide and effective education to adolescents and young adults will help raise awareness, increase knowledge, and consequently change attitudes and listening habits.     

Hearing in Noise Test Brazil: standardization for young adults with normal hearing

IntroductionIndividuals with the same ability of speech recognition in quiet can have extremely different results in noisy environments.ObjectiveTo standardize speech perception in adults with normal hearing in the free field using the Brazilian Hearing in Noise Test.MethodsContemporary, cross-sectional cohort study. 79 adults with normal hearing and without cognitive impairment participated in the study. Lists of Hearing in Noise Test sentences were randomly in quiet, noise front, noise right, and noise left.ResultsThere were no significant differences between right and left ears at all frequencies tested (paired t − 1 test). Nor were significant differences observed when comparing gender and interaction between these conditions. A difference was observed among the free field positions tested, except in the situations of noise right and noise left.ConclusionResults of speech perception in adults with normal hearing in the free field during different listening situations in noise indicated poorer performance during the condition with noise and speech in front, i.e., 0°/0°. The values found in the standardization of the Hearing in Noise Test free field can be used as a reference in the development of protocols for tests of speech perception in noise, and for monitoring individuals with hearing impairment.     

The interaction of hearing loss and level-dependent hearing protection on speech recognition in noise

Abstract

Objectives: To determine the effects of different control settings of level-dependent hearing protectors on speech recognition performance in interaction with hearing loss. Design: Controlled laboratory experiment with two level-dependent devices (Peltor^® PowerCom Plus? and Nacre QuietPro^®) in two military noises. Study sample: Word recognition scores were collected in protected and unprotected conditions for 45 participants grouped into four hearing profile categories ranging from within normal limits to moderate-to-severe hearing loss. Results: When the level-dependent mode was switched off to simulate conventional hearing protection, there were large differences across hearing profile categories regarding the effects of wearing the devices on speech recognition in noise; participants with normal hearing showed little effect while participants in the most hearing-impaired category showed large decrements in scores compared to unprotected listening. Activating the level-dependent mode of the devices produced large speech recognition benefits over the passive mode at both low and high gain pass-through settings. The category of participants with the most impaired hearing benefitted the most from the level-dependent mode. Conclusions: The findings indicate that level-dependent hearing protection circuitry can provide substantial benefits in speech recognition performance in noise, compared to conventional passive protection, for individuals covering a wide range of hearing losses.