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

Abstract

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.

Speech Recognition in Noise Using Binaural Diotic and Antiphasic Digits-in-Noise in Children: Maturation and Self-Test Validity

“…42,43 Other studies have found that BILDs increase with increasing age. 44 Some studies report that spatial release of masking is adult-like at a young age (e.g., 4-6 years) [45][46][47] while others show a developmental trajectory. 26,48,49 Practically, age-specific normative criteria should be available for the diotic and antiphasic DIN, to relate the results of children tested to that of their peers.…”

A Danish Sentence Corpus for Assessing Speech Recognition in Noise in School-Age Children

“…It has been found to be usable with children aged four and above ( Neumann et al., 2012 ; Wagener et al., 2006 ). Another speech test that was designed for the use with children is ‘FreeHear,’ which is available in British English ( Moore et al., 2019 ). In this test, three spoken digits are presented against a background of babble noise.…”

Improved Sensitivity of Digits-in-Noise Test to High-Frequency Hearing Loss

“…Recently, Moore and colleagues (2019) developed a DIN test that uses sound-field presentation of digits against a multi-talker babble masker (“FreeHear”). The masker is either co-located with the digits (0°), or presented 90° either side of the participant, enabling measurement of spatial ‘release from masking’, the benefit received from a spatial mis-match between target and masker.…”