Testing of Listening Difficulty – Universal Test (ToLD-U)

Purpose

ToLD-U measures the ability to recognise and understand sentences in noise and reverberation. ToLD-U has been designed to realistically simulate listening in a classroom or a noisy social gathering. In addition to a frontal target talker there are multiple competing talkers at different distances and directions. People use both their ability to recognise individual speech sounds and their knowledge of language to understand and repeat back as many words in each sentence as they can. The term “Universal” in the title has been used because the test has been designed with the aim of being sensitive to almost anything that could cause a listening deficit in noise in real life. Specifically, it is designed to be sensitive to deficits in basic auditory processing of complex sounds, speech sound identification, segregation of target speech from competing speech with the aid of spatial cues, language ability, working memory, and selective attention. The measurement result is the signal-to-noise ratio (SNR) at which the person can understand 75% of the words in the sentence.

ToLD-U is intended to be the first test delivered to a client to determine if the person has a deficit in speech understanding in noise and reverberation and if so, the magnitude of that deficit. By itself, ToLD-U cannot determine the reason for any such deficit, but in conjunction with other tests, often can reveal the dominant cause. ToLD-U is suitable for children from age 6.0 years upwards or for adults of any age. Normative data for adults are based on adults in the age range 18 to 40 years.

Nature of Task

The test comprises sentences from five to twelve words with high redundancy, spoken in a casual manner. The client repeats as many words as they understand, and the clinician indicates on the screen which words were correctly perceived. Whenever more than 75% of the words are correct, the next sentence is automatically presented at a more difficult SNR. Conversely, if less than 75% are correct, the SNR is increased for the next sentence. The test moves through a practice phase, a hunting phase in which the SNR approaches the value where 75% of words are understood, and then the measurement phase. The test result, the speech reception threshold expressed as a SNR, is obtained by averaging the SNR of all trials presented during the measurement phase. To increase the precision, and better reflect the amount of information conveyed, words with more than one morpheme (e.g. kick – ed) are scored for each morpheme, rather than for the word as a whole.

The test screen, which is visible to the clinician but not the client, is shown below.

Screenshot from version 2025.8.29a

The test is presented with the background noise approximately 40 dB above speech reception threshold in quiet. If the client has been indicated to have a sensorineural or mixed hearing loss, and thresholds have been provided, then the elevation above speech reception threshold in quiet is appropriately less to allow for loudness recruitment.

Scoring

Normative data exists for Australian children and adults listening to the Australian-accented version of ToLD-U and for British children listening to the British-accented version of ToLD-U. Scoring is computer assisted, and at the end of the test, the individual’s Speech Reception Threshold in noise is displayed in several formats. These comprise SNR in dB, z-score (i.e. number of standard deviations above mean for that age), and percentile. The z-score and percentile are automatically corrected for age, based on the normative data built into the test.

Scientific studies

ToLD-U has been used in research studies at Macquarie University, University of Melbourne and the University of Manchester, the results of which have started to appear in scientific articles, with more to follow. The following graphs show some of the results. Figure 1 shows the relationship between ToLD-U Speech Reception Thresholds in noise (SRT) in adults in Australia (with more negative scores representing better performance) and language ability measured with AudiCloze.

Figure 1. Speech reception threshold in noise measured with ToLD-U versus language ability as measured with AudiCloze. Red symbols represent people with English as a second language and blue symbols represent native English speaker. From Luengtaweekul et al (2025, submitted).

Figure 2 similarly shows the association between ToLD-U SRT and speech understanding in noise in British children The most plausible reason for the significant association is that language ability helps with speech understanding in noise, but it is also possible that superior speech understanding in noise helps a child develop superior language ability.

Figure 2. Speech reception threshold in noise measured with ToLD-U, expressed as age-corrected z-scores versus the age-corrected language ability as measured by AudiCloze. From Zhou et al (2025a).

Figure 3 shows how ToLD-U performance in a representative sample of British children is related to identification of nonsense syllables in noise and reverberation, measured with LiSN-R. Results are shown for children with English as their native language and for children with English as a second language (ESL).

Figure 3. ToLD-U (sentences) versus LiSN-R (nonsense syllables) identification in noise and reverberation. Both are expressed as z-scores. Filled red circles and red dashed line represent the native English-speaking group, while hollow blue circles and blue dotted line represent the ESL group.

Figure 4 shows how performance on ToLD-U varies with age for children and adults in Australia.

Figure 4. Speech reception threshold in noise for ToLD-U. Blue circles are for native English talkers and red crosses are for those with English as an additional language. The solid blue curve is a two-segment linear regression fitted to the data for native English talkers under 40 years of age. From Dillon et al, (2025, In press).

Published Science

Dillon H, Gaikwad S, Luengtaweekul P, Buchholz J, and Cameron S. (In press). Development of the Test of Listening Difficulties - Universal (ToLD-U) and Australian normative data in children and adults. JSLHR. https://doi.org/10.1080/14992027.2019.1689431

Luengtaweekul P, Sharma M, Alnafjan F, Dillon H. (Submitted) The Impact of a Second Language and Language Proficiency on Sentence Understanding in Noise in Young Normal-Hearing Adults.

Zhou, X., Dillon, H., Tomlin, D., Burgoyne, K., Gurteen, H., Nixon, G., Gudkar, A. I., & Heinrich, A. (2025a). Assessing Language Skills as a Predictor of Children's Listening Difficulties: Validation and Reference Data on a New Auditory Language Task. Ear Hear. Early online. https://doi.org/10.1097/AUD.0000000000001715

Zhou, X., Dillon, H., Tomlin, D., Burgoyne, K., Gurteen, H., Nixon, G., Cameron, S., Gudkar, A. I., & Heinrich, A. (2025b). Effects of age, sex, language ability and second language listening on children's recognition of nonwords and sentences in noise and reverberation. Int J Audiol, 1-14. Early Online. https://doi.org/10.1080/14992027.2025.2552264