Assessment of speech recognition abilities in quiet and in noise: a comparison between self-administered home testing and testing in the clinic for adult cochlear implant users

Remote assessment of music perception in pediatric cochlear implant recipients

OBJECTIVE

The primary objective of this study was to explore the feasibility of remotely assessing music perception in paediatric cochlear implant (CI) recipients. Pitch direction discrimination (PDD) and timbre recognition (TR) tests were administered remotely. We aimed to provide insights into the potential benefits and challenges of remote assessments.

DESIGN

The study was exploratory in nature. All participants underwent remote assessments for the PDD and TR tests. Eight participants completed both online and face-to-face tests. Supervising parents in remote tests completed the System Usability Scale (SUS).

STUDY SAMPLE

A cohort of 27 children with CI, averaging 11.19 years of age, participated in this study.

RESULTS

In the online condition, the average PDD score was 3.29 semitones (st), the TR score was 37.86%, and the average duration for PDD and TR testing was 9.98 and 6.18 minutes, respectively. Face-to-face sessions had an average PDD score of 3.00 st, a TR score of 32.81% and durations of 10.20 and 5.42 minutes for PDD and TR tests, respectively. The SUS score averaged 64.04.

CONCLUSION

These findings contribute to the growing body of knowledge supporting the integration of remote assessments in audiological practices.

Experienced Adult Cochlear Implant Users Show Improved Speech Recognition When Target Fitting Parameters Are Applied

OBJECTIVES

The aim of the present study was to investigate whether prediction models built by de Graaff et al. (2020 ) can be used to improve speech recognition in experienced adult postlingual implanted Cochlear CI users. de Graaff et al. (2020 ) found relationships between elevated aided thresholds and a not optimal electrical dynamic range (<50 CL or >60 CL), and poorer speech recognition in quiet and in noise. The primary hypothesis of the present study was that speech recognition improves both in quiet and in noise when the sound processor is refitted to match targets derived from the prediction models from de Graaff et al. (2020 ). A second hypothesis was that subjectively, most of the CI users would find the new setting too loud because of an increase in C levels, and therefore, prefer the old settings.

DESIGN

A within-participant repeated measures design with 18 adult Cochlear CI users was used. T- and C-levels were changed to "optimized settings," as predicted by the model of de Graaff et al. (2020 ). Aided thresholds, speech recognition in quiet, and speech recognition in noise were measured with the old settings and after a 4-week acclimatization period with the optimized settings. Subjective benefit was measured using the Device Oriented Subjective Outcome Scale questionnaire.

RESULTS

The mean electrical dynamic range changed from 41.1 (SD = 6.6) CL to 48.6 (SD = 3.0) CL. No significant change in aided thresholds was measured. Speech recognition improved for 16 out of 18 participants and remained stable for 2 participants. Average speech recognition scores in quiet significantly improved by 4.9% (SD = 3.8%). No significant change for speech recognition in noise was found. A significant improvement in subjective benefit was found for one of the Device Oriented Subjective Outcome subscales (speech cues) between the old and optimized settings. All participants chose to keep the optimized settings at the end of the study.

CONCLUSIONS

We were able to improve speech recognition in quiet by optimizing the electrical dynamic range of experienced adult CI users, according to the prediction models built by de Graaff et al. (2020 ). There was no significant change in aided thresholds nor in speech recognition in noise. The findings of the present study suggest that improved performance for speech recognition in quiet in adult Cochlear CI users can be achieved by setting the dynamic range as close as possible to values between 50 and 60 CL when the volume level is at 10.

The multilingual digits-in-noise (DIN) test: development and evaluation

OBJECTIVE

To develop a methodologically uniform digits-in-noise (DIN) test in 17 different languages.

DESIGN

The DIN test was developed for Android devices as an extension to the open-access Hearing Test™ app, available on the Google Play store. It utilised professionally recorded female speech, speech-shaped noise, a digit scoring method and a variable step size. The test was adaptively optimised and evaluated as the results of tests taken online by users of the app became available.

STUDY SAMPLE

Optimisation using 35,534 ears, evaluation using 6012 ears.

RESULTS

Optimisation improved the slopes of the psychometric functions for all languages by an average of 6.8%/dB. Evaluation included calculation of normative speech reception thresholds (SRTs) and estimation of test-retest standard deviations. Normative values for SRTs ranged from -14.2 dB SNR (95% CI -14.3 to -14.0) for Chinese to -11.2 dB SNR (95% CI -11.3 to -11.1) for Japanese, with reliability estimates ranging from 0.48 dB (95% CI 0.36-0.64) for Portuguese to 0.91 dB (95% CI 0.73-1.21) for Romanian.

CONCLUSIONS

The optimisation of each language version was confirmed by the improvement in the slopes of the psychometric functions. The normative values obtained from the test evaluation were in agreement with literature data.

TRIAL REGISTRATION

Science Support Centre of Wroclaw Medical University BW-59/2020.

Remote self-testing for adult cochlear implant users: the effect of wireless streaming on speech recognition in noise

OBJECTIVES

Wireless sound transfer methods for cochlear implant sound processors have become popular for remote self-assessed hearing tests. The aim of this study was to determine (1) spectral differences in stimuli between different wireless sound transfer options and (2) the effect on outcomes of speech recognition tests in noise.

DESIGN

In study 1, the frequency response of different streaming options (Phonak Roger Select, Cochlear Mini Mic 2+, telecoil and Bluetooth connection) was measured by connecting headphones to CI sound processors. Study 2 followed a repeated measures design in which digits-in-noise (DIN) tests were performed using wireless streaming to sound processors from Cochlear, Advanced Bionics, and MED-EL.

STUDY SAMPLE

20 normal hearing participants.

RESULTS

Differences in frequency response between loudspeaker and wireless streaming conditions were minimal. We did not find significant difference in DIN outcome (F4,194 = 1.062, p = 0.376) between the wireless transfer options with the Cochlear Nucleus 7 processor. No significant difference in DIN outcomes was found between Bluetooth streaming and the loudspeaker condition for all of the three tested brands. The mean standard error of measurement was 0.72 dB.

CONCLUSIONS

No significant differences in DIN test outcomes between wireless sound transfer and the reference method were found.

Comparison of Psychometric Functions Measured Using Remote Testing and Laboratory Testing

The use of remote testing to collect behavioral data has been on the rise, especially after the COVID-19 pandemic. Here we present psychometric functions for a commonly used speech corpus obtained in remote testing and laboratory testing conditions on young normal hearing listeners in the presence of different types of maskers. Headphone use for the remote testing group was checked by supplementing procedures from prior literature using a Huggins pitch task. Results revealed no significant differences in the measured thresholds using the remote testing and laboratory testing conditions for all the three masker types. Also, the thresholds measured obtained in these two conditions were strongly correlated for a different group of young normal hearing listeners. Based on the results, excellent outcomes on auditory threshold measurements where the stimuli are presented both at levels lower than and above an individual's speech-recognition threshold can be obtained by remotely testing the listeners.

Development of the Mandarin Digit-in-Noise Test and Examination of the Effect of the Number of Digits Used in the Test

OBJECTIVES

The study aimed to develop and validate the Mandarin digit-in-noise (DIN) test using four digit (i.e., two-, three-, four-, and five-digit) sequences. Test-retest reliability and criterion validity were evaluated. How the number of digits affected the results was examined. The research might lead to more informed choice of DIN tests for populations with specific cognitive needs such as memory impairment.

DESIGN

The International Collegium of Rehabilitative Audiology guideline for developing the DIN was adapted to create test materials. The test-retest reliability and psychometric function of each digit sequence were determined among young normal-hearing adults. The criterion validity of each digit sequence was determined by comparing the measured performance of older adult hearing aid users with that obtained from two other well-established sentence-in-noise tests: the Mandarin hearing-in-noise test and the Mandarin Chinese matrix test. The relation between the speech reception thresholds (SRTs) of each digit sequence of the DIN test and working memory capacity measured using the digit span test and the reading span test were explored among older adult hearing aid users. Together, the study sample consisted of 54 young normal-hearing adults and 56 older adult hearing aid users.

RESULTS

The slopes associated with the two-, three-, four-, and five-digit DIN test were 16.58, 18.79, 20.42, and 21.09 %/dB, respectively, and the mean SRTs were -11.11, -10.99, -10.56, and -10.02 dB SNR, respectively. Test-retest SRTs did not differ by more than 0.74 dB across all digit sequences, suggesting good test-retest reliability. Spearman rank-order correlation coefficients between SRTs obtained using the DIN across the four digit (i.e., two-, three-, four-, and five-digit) sequences and the two sentence-in-noise tests were uniformly high ( rs = 0.9) across all participants, when data from all participants were considered. Results from the digit span test and reading span test correlated significantly with the results of the five-digit sequences ( rs = -0.37 and -0.42, respectively) but not with the results of the two-, three-, and four-digit sequences among older hearing aid users.

CONCLUSIONS

While the three-digit sequence was found to be appropriate for clinical use for assessment of auditory perception, the two-digit sequence could be used for hearing screening. The five-digit sequence could be difficult for older hearing aid users, and with its SRT related to working memory capacity, its use in the evaluation of speech perception should be investigated further. The Mandarin DIN test was found to be reliable, and the findings are in line with SRTs obtained using standardized sentence tests, suggesting good criterion validity.

Measurement and optimisation of the perceptual equivalence of the Dutch consonant-vowel-consonant (CVC) word lists using synthetic speech and list pairs

OBJECTIVES

(1) to determine whether the standard Dutch word lists for speech audiometry are equally intelligible in normal-hearing listeners (Experiment 1), (2) to investigate whether synthetic speech can be used to create word lists (Experiment 1) and (3) to determine whether the list effect found in Experiment 1 can be reduced by combining two lists into pairs (Experiment 2).

DESIGN

Participants performed speech tests in quiet with the original (natural) and synthetic word lists (Experiment 1.). In Experiment 2, new participants performed speech tests with list pairs from the original lists constructed from the results of Experiment 1.

STUDY SAMPLES

Twenty-four and twenty-eight normal-hearing adults.

RESULTS

There was a significant list effect in the natural speech lists; not in the synthetic speech lists. Variability in intelligibility was significantly higher in the former, with list differences up to 20% at fixed presentation levels. The 95% confidence interval of a list with a score of approximately 70% is around 10%-points wider than of a list pair.

CONCLUSIONS

The original Dutch word lists show large variations in intelligibility. List effects can be reduced by combining two lists per condition. Synthetic speech is a promising alternative to natural speech in speech audiometry in quiet.

Effect of Realistic Test Conditions on Perception of Speech, Music, and Binaural Cues in Normal-Hearing Listeners

PURPOSE

The purpose of this study was to determine the feasibility of online testing in a quiet room for three auditory perception experiments in normal-hearing listeners: speech, music, and binaural cue.

METHOD

Under Experiment 1, sentence perception was measured using fixed signal-to-noise ratios (SNRs: +10 dB, 0 dB, and -10 dB) and using adaptive speech reception threshold (SRT) procedures. The correct scores were compared between quiet room and soundproof booth listening environments. Experiment 2 was designed to compare melodic contour identification between the two listening environments. Melodic contour identification was assessed with 1, 2, and 4 semitone spacings. Under Experiment 3, interaural level difference (ILD) and interaural time differences (ITD) were measured as a function of carrier frequency. For both measures, two modulated tones (400-ms duration and 100-Hz modulation rate) were sequentially presented through headphones to both ears, and subjects were asked to indicate whether the sound moved to the left or right ear. The measured ITD and ILD were then compared between the two listening environments.

RESULTS

There were no significant differences in any outcome measures (SNR- and SRT-based speech perception, melodic contour identification, and ITD/ILD) between the two listening environments.

CONCLUSIONS

These results suggest that normal-hearing listeners may not require a controlled listening environment in any of the three auditory assessments. As comparable data can be obtained via the online testing tool, using the online auditory experiments is recommended.

An online implementation of a measure of spectro-temporal processing by cochlear-implant listeners

The spectro-temporal ripple for investigating processor effectiveness (STRIPES) test is a psychophysical measure of spectro-temporal resolution in cochlear-implant (CI) listeners. It has been validated using direct-line input and loudspeaker presentation with listeners of the Advanced Bionics CI. This article investigates the suitability of an online application using wireless streaming (webSTRIPES) as a remote test. It reports a strong across-listener correlation between STRIPES thresholds obtained using laboratory testing with loudspeaker presentation vs remote testing with streaming presentation, with no significant difference in STRIPES thresholds between the two measures. WebSTRIPES also produced comparable and robust thresholds with users of the Cochlear CI.

Novel cochlear implant assessment tool: Comparative analysis of children and adults

Objectives

To analyse the results of children and adults with cochlear implants (CIs) in pure tone audiometry (PTA) and speech perception tests. Tests were performed in two ways: using loudspeakers in the sound booth (SB) and with direct audio input (DAI) employing the Cochlear Latin America BOX (CLABOX).

Methods

Fifty individuals (33 adults and 17 children) participated in the study, including children aged between 8 and 13 years; of these, 15 users had bilateral CIs, 35 had unilateral CIs, and all had severe to profound bilateral sensorineural hearing loss. All participants were evaluated in the SB with loudspeakers and the CLABOX with DAI. The following evaluations were conducted: PTA, speech recognition tests with the hearing in noise test (HINT).

Results

The results for PTA and HINT conducted in SB and with CLABOX presented no significant difference between children and adults.

Conclusion

The CLABOX tool presents a new possible method to evaluate PTA and speech recognition tests in adults and children, with results comparable to the conventional evaluation in the SB.

Remote Monitoring of Adult Cochlear Implant Recipients Using Digits-in-Noise Self-Testing

PURPOSE

The COVID-19 pandemic has accelerated the uptake and scope of telehealth. This study determined the accuracy and reliability of a smartphone digits-in-noise (DIN) test when conducted by adult cochlear implant (CI) recipients in a simulated home environment compared with a clinic setup. Perceptions of remote monitoring using speech-in-noise (SIN) testing were also explored.

METHOD

Thirty-three adult CI recipients between 18 and 78 years of age (M = 46.7, SD = ±20.4) conducted the DIN test in a simulated home environment and a clinic setup. Test-retest reliability across the two environments and comparisons between test settings were evaluated. A survey explored the perceptions of adult CI recipients regarding remote monitoring and use of the DIN self-test.

RESULTS

Mean-aided speech reception thresholds (SRTs) in the clinic and simulated home environment test conditions and clinic and simulated home environment retest conditions did not differ significantly. Mean test-retest SRTs in the clinic and simulated home environment were significantly different (p < .05). High intraclass correlation coefficient and low standard error of measurement scores reflected good and excellent reliability between test-retest measures and between clinic and simulated home environment measures. Most participants were positive about the possibility of using the DIN test at home to self-assess speech perception, although some test adjustments such as including training items and a less adverse starting signal-to-noise ratio may be required.

CONCLUSION

Adult CI recipients can use the smartphone DIN test to self-assess aided SIN performance in a home environment with accuracy and reliability relatively similar to clinic testing.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.20044418.

FORUM: Remote testing for psychological and physiological acoustics

Acoustics research involving human participants typically takes place in specialized laboratory settings. Listening studies, for example, may present controlled sounds using calibrated transducers in sound-attenuating or anechoic chambers. In contrast, remote testing takes place outside of the laboratory in everyday settings (e.g., participants' homes). Remote testing could provide greater access to participants, larger sample sizes, and opportunities to characterize performance in typical listening environments at the cost of reduced control of environmental conditions, less precise calibration, and inconsistency in attentional state and/or response behaviors from relatively smaller sample sizes and unintuitive experimental tasks. The Acoustical Society of America Technical Committee on Psychological and Physiological Acoustics launched the Task Force on Remote Testing (https://tcppasa.org/remotetesting/) in May 2020 with goals of surveying approaches and platforms available to support remote testing and identifying challenges and considerations for prospective investigators. The results of this task force survey were made available online in the form of a set of Wiki pages and summarized in this report. This report outlines the state-of-the-art of remote testing in auditory-related research as of August 2021, which is based on the Wiki and a literature search of papers published in this area since 2020, and provides three case studies to demonstrate feasibility during practice.

Home-Based Speech Perception Monitoring for Clinical Use With Cochlear Implant Users

Speech-perception testing is essential for monitoring outcomes with a hearing aid or cochlear implant (CI). However, clinical care is time-consuming and often challenging with an increasing number of clients. A potential approach to alleviating some clinical care and possibly making room for other outcome measures is to employ technologies that assess performance in the home environment. In this study, we investigate 3 different speech perception indices in the same 40 CI users: phoneme identification (vowels and consonants), digits in noise (DiN) and sentence recognition in noise (SiN). The first two tasks were implemented on a tablet and performed multiple times by each client in their home environment, while the sentence task was administered at the clinic. Speech perception outcomes in the same forty CI users showed that DiN assessed at home can serve as an alternative to SiN assessed at the clinic. DiN scores are in line with the SiN ones by 3–4 dB improvement and are useful to monitor performance at regular intervals and to detect changes in auditory performance. Phoneme identification in quiet also explains a significant part of speech perception in noise, and provides additional information on the detectability and discriminability of speech cues. The added benefit of the phoneme identification task, which also proved to be easy to administer at home, is the information transmission analysis in addition to the summary score. Performance changes for the different indices can be interpreted by comparing against measurement error and help to target personalized rehabilitation. Altogether, home-based speech testing is reliable and proves powerful to complement care in the clinic for CI users.

Comparing the Speech Perception of Cochlear Implant Users with Three Different Finnish Speech Intelligibility Tests in Noise

Background: A large number of different speech-in-noise (SIN) tests are available for testing cochlear implant (CI) recipients, but few studies have compared the different tests in the same patient population to assess how well their results correlate. Methods: A clinically representative group of 80 CI users conducted the Finnish versions of the matrix sentence test, the simplified matrix sentence test, and the digit triplet test. The results were analyzed for correlations between the different tests and for differences among the participants, including age and device modality. Results: Strong and statistically significant correlations were observed between all of the tests. No floor or ceiling effects were observed with any of the tests when using the adaptive test procedure. Age or the length of device use showed no correlation to SIN perception, but bilateral CI users showed slightly better results in comparison to unilateral or bimodal users. Conclusions: Three SIN tests that differ in length and complexity of the test material provided comparable results in a diverse CI user group.

Testing Speech Perception with Cochlear Implants Through Digital Audio Streaming in a Virtual Sound Booth: A Feasibility Study

OBJECTIVE

 For patients who have received cochlear implants (CIs), speech-perception testing requires specialized equipment. This limits locations where these services can be provided, which can introduce barriers for provision of care. Providing speech test stimuli directly to the CI via wireless digital audio streaming (DAS) or wired direct audio input (DAI) allows for testing without the need for a sound booth (SB). A few studies have investigated the use of DAI for testing speech perception in CIs, but none have evaluated DAS. The goal of this study was to compare speech perception testing in CI users via DAS versus a traditional SB to determine if differences exist between the two presentation modes. We also sought to determine whether pre-processing the DAS signal with room acoustics (reverberation and noise floor) to emulate the SB environment would affect performance differences between the SB and DAS.

DESIGN

 In Experiment 1, speech perception was measured for monosyllabic words in quiet and sentences in quiet and in noise. Scores were obtained in a SB and compared to those obtained via DAS with unprocessed speech (DAS-U) for 11 adult CI users (12 ears). In Experiment 2, speech perception was measured for sentences in noise, where both the speech and noise stimuli were pre-processed to emulate the SB environment. Scores were obtained for 11 adult CI users (12 ears) in the SB, via DAS-U, and via DAS with the processed speech (DAS-P).

RESULTS

 For Experiment 1, there was no significant difference between SB and DAS-U conditions for words or sentences in quiet. However, DAS-U scores were significantly better than SB scores for sentences in noise. For Experiment 2, there was no significant difference between the SB and DAS-P conditions. Similar to Experiment 1, DAS-U scores were significantly better than SB or DAS-P scores.

CONCLUSIONS

 By pre-processing the test materials to emulate the noise and reverberation characteristics of a traditional SB, we can account for differences in speech-perception scores between those obtained via DAS and in a SB.

The digit triplet test: a scoping review

OBJECTIVE

This review article presents an overview of all Digit Triplet Tests (DTT) and digits-in-noise tests (DIN) and their variations in language, speech material, masking noise, test procedures, and targeted population. The effects on aspects of validity, reliability, and feasibility are investigated.

DESIGN

Scoping review.

STUDY SAMPLE

All studies referring to the DTT and DIN were collected from Pubmed and Embase. Search terms "digit triplet test" and "digits in noise" were used. Citations of selected articles were scanned backwards in time (the bibliography of the already selected research article) and forward in time (articles that cited the already selected research article). The search terms yielded 95 results in total. Eventually, 39 papers were selected.

RESULTS

Analyses showed psychometric reference-curves with steep slopes and speech reception thresholds with high measurement precision which are strongly associated with pure tone audiometry. High sensitivity and specificity to detect elevated pure tone thresholds were noted for test variants. Certain procedural modifications of the DTT and DIN can further improve the test. Additionally, large-scale application of the DTT and DIN is feasible.

CONCLUSION

The DTT and DIN are a very valuable tool for screening and diagnostics for a wide variety of populations.

Binaural summation, binaural unmasking and fluctuating masker benefit in bimodal and bilateral adult cochlear implant users

OBJECTIVES

The number of bilateral adult cochlear implant (CI) users and bimodal CI users is expanding worldwide. The addition of a hearing aid (HA) in the contralateral non-implanted ear (bimodal) or a second CI (bilateral) can provide CI users with some of the benefits associated with listening with two ears. Our was to examine whether bilateral and bimodal CI users demonstrate binaural summation, binaural unmasking and a fluctuating masker benefit.

METHODS

Direct audio input was used to present stimuli to 10 bilateral and 10 bimodal Cochlear^TM CI users. Speech recognition in noise (speech reception threshold, SRT) was assessed monaurally, diotically (identical signals in both devices) and dichotically (antiphasic speech) with different masking noises (steady-state and interrupted), using the digits-in-noise test.

RESULTS

Bilateral CI users demonstrated a trend towards better SRTs with both CIs than with one CI. Bimodal CI users showed no difference between the bimodal SRT and the SRT for CI alone. No significant differences in SRT were found between the diotic and dichotic conditions for either group. Analyses of electrodograms created from bilateral stimuli demonstrated that substantial parts of the interaural speech cues were preserved in the Advanced Combination Encoder, an n-of-m channel selection speech coding strategy, used by the CI users. Speech recognition in noise was significantly better with interrupted noise than with steady-state masking noise for both bilateral and bimodal CI users.

CONCLUSION

Bilateral CI users demonstrated a trend towards binaural summation, but bimodal CI users did not. No binaural unmasking was demonstrated for either group of CI users. A large fluctuating masker benefit was found in both bilateral and bimodal CI users.

Reward Enhances Online Participants' Engagement With a Demanding Auditory Task

Online recruitment platforms are increasingly used for experimental research. Crowdsourcing is associated with numerous benefits but also notable constraints, including lack of control over participants' environment and engagement. In the context of auditory experiments, these limitations may be particularly detrimental to threshold-based tasks that require effortful listening. Here, we ask whether incorporating a performance-based monetary bonus improves speech reception performance of online participants. In two experiments, participants performed an adaptive matrix-type speech-in-noise task (where listeners select two key words out of closed sets). In Experiment 1, our results revealed worse performance in online (N = 49) compared with in-lab (N = 81) groups. Specifically, relative to the in-lab cohort, significantly fewer participants in the online group achieved very low thresholds. In Experiment 2 (N = 200), we show that a monetary reward improved listeners' thresholds to levels similar to those observed in the lab setting. Overall, the results suggest that providing a small performance-based bonus increases participants' task engagement, facilitating a more accurate estimation of auditory ability under challenging listening conditions.

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

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.

Performance and Reliability of a Smartphone Digits-in-Noise Test in the Sound Field

Purpose This study compared the speech reception thresholds (SRTs) and test-retest reliability of the smartphone digits-in-noise (DIN) test coupled to various sound-field transducers. Method Fifty normal-hearing participants (bilateral pure- tone thresholds 0.5-8kHz ≤ 15dB HL) between the ages of 18 and 25 years (M = 20, SD = ±1.9) were recruited. The study used a repeated measure counterbalanced Latin square design to compare the SRTs of the smartphone DIN test recorded with earphones, 2 smartphone speakers, and 2 external loudspeakers in a sound booth. Test-retest reliability across sound field conditions was also determined. Results Mean SRTs across earphone and different sound field transducers ranged from -11.3 (SD = 0.8) to -11.7 (SD = 1.2). SRTs across the 4 different loudspeaker transducers and earphones were not significantly different (p > .05) between test and retest sessions. Conclusion The smartphone DIN test is reliable and can be conducted using various sound field transducers in a sound booth. To allow home-based testing without earphones, with special application to aided performance for speech-in-noise testing, the smartphone DIN test should be evaluated in home environments.