Apr 16, 2026
The irrelevant babble effect in individuals with autism spectrum disorder
- Lejla Alikadic1,
- Jan Philipp Röer1
- 1Witten/Herdecke University
External link: https://osf.io/u567f/overview
Protocol Citation: Lejla Alikadic, Jan Philipp Röer 2026. The irrelevant babble effect in individuals with autism spectrum disorder. protocols.io https://dx.doi.org/10.17504/protocols.io.kqdg3mdw7l25/v1
Manuscript citation:
Alikadic, L., & Röer, J. P. (2026). Data from three experiments on auditory attention and distraction in autistic and nonautistic adults. Data in brief, 64, 112431. https://doi.org/10.1016/j.dib.2025.112431
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We used this protocol and it's working
Created: April 12, 2026
Last Modified: April 16, 2026
Protocol Integer ID: 314868
Keywords: Auditory distraction, Auditory distraction, Irrelevant sound effect, Irrelevant babble effect, Intensity effect, Serial recall task, Autism spectrum disorder, irrelevant babble effect in individual, irrelevant babble effect, non autistic young adult, autism spectrum disorder, distractor intensity on serial recall performance, channel speech, distractor intensity, serial recall performance
Abstract
Using a within-between-subjects design, we measured the effect of multi-channel speech compared to single- and dual-channel speech and that of distractor intensity on serial recall performance comparing autistic and non autistic young adults.
Materials
The irrelevant auditory distractor sequences consisted of sentences spoken from a physiology textbook that were digitally recorded at a sample rate of 44.1 kHz and 16-bit encoding using six different text-to-speech voices.
- The single-channel speech condition included a single female voice
- The dual-channel speech condition included a female and a male voice playing simultaneously
- The multi-channel speech condition included three female and three male voices playing simultaneously
- In the low-intensity condition, the distractors were presented at a level of 45 dB(A)
- In the high-intensity condition, the distractors were presented at a level of 75 dB(A)
Each distractor sequence lasted eight seconds and was synchronized with the onset of the first digit from the serial recall task.
The intensity of the auditory distractor sequences was measured using a professional hand-held sound level meter that was inserted through the opening of a polystyrene ear.
Experimental design
The experiment employs a 2 x 2 x 3 mixed design, with group (autistic individuals, nonautistic individuals) as the between-subjects factor, and number of voices (single-channel speech, dual-channel speech, multi-channel speech) and distractor intensity (low, high) as within-subjects factors. Participants are required to complete a standard serial recall task, and serial recall performance is scored as the dependent variable using a strict serial-recall criterion.
Data collection
Prior to participation, written informed consent was obtained from all participants.
Pretests included measuring intellectual and language abilities (Liepmann et al., 2012) and autism severity (Allison et al., 2012).
In the laboratory, participants completed a visual-verbal serial recall task on a computer.
Auditory distractors were simultaneously presented via headphones in randomized order.
Participants
The total number of participants was 141. The autistic group consisted of 49 individuals (23 females, 23 males, and 2 individuals who identified as “other/not specified”) with an average age of 29.6 years (SD = 6.1). The nonautistic group consisted of 92 individuals (57 females, 34 males, and 1 individual who identified as “other/not specified”) with an average age of 23.1 years (SD = 3.5).
Eligibility criteria were:
Formal diagnosis of
- autistic disorder (previously termed "high-functioning"),
- Asperger's disorder,
- autism spectrum disorder "without accompanying intellectual impairment/without accompanying language impairment" (DSM-IV-TR, DSM-5; American Psychiatric Association, 2000, 2013), or equivalent diagnoses (ICD-10, ICD-11; World Health Organization, 2016, 2019).
Procedure
Participants were individually seated in a sound-attenuated booth in the university laboratory.
In the serial recall task, sequences of eight to-be remembered digits from the set {1, 2, ...,
9} were shown at a rate of 1 Hz (800 ms on, 200 ms off) on a computer screen, while irrelevant auditory distractors were presented through headphones.
Participants were told beforehand that all background sounds are irrelevant and that they should ignore them.
A total of six different distractor sequence conditions were presented:
Single-channel speech soft, single-channel speech loud,
dual-channel speech soft, dual-channel speech loud,
multi-channel speech soft, multi-channel speech loud.
The experiment was divided into two blocks and consisted of 76 trials.
The training block consisted of four trials.
In this block, the serial recall task was presented without auditory distractors.
The experimental block consisted of 12 trials per condition (72 trials).
The experimental and training block together lasted on average 27 minutes.
Analysis
As preregistered, we ran a 2 x 2 x 3 repeated-measures MANOVA with group (autistic individuals, nonautistic individuals) as between-subjects factor, and intensity (low, high) and complexity (single-channel speech, dual-channel speech, multi-channel speech) as within-subjects factors.
We used orthogonal contrasts on the auditory condition variable to test whether there is an irrelevant babble effect (i.e., a significant decrease in disruption of serial recall in the multi-channel conditions relative to the single- und dual-channel conditions combined).
We tested whether there is an intensity effect (i.e., a significant increase in disruption of serial recall in the high-intensity conditions relative to the low-intensity conditions).
In exploratory analyses, we examined whether the irrelevant babble and intensity effect were subject to habituation.
Protocol references
Alikadic, L., & Röer, J. P. (2022). Loud auditory distractors are more difficult to ignore after all: A preregistered replication study with unexpected results. Experimental Psychology, 69(3), a000554.
Alikadic, L., & Röer, J. P. (2026). Data from three experiments on auditory attention and distraction in autistic and nonautistic adults. Data in brief, 64, 112431. https://doi.org/10.1016/j.dib.2025.112431
Allison, C., Auyeung, B., & Baron-Cohen, S. (2012). Toward brief “red flags” for autism screening: The short autism
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American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). American Psychiatric Association Publishing. https://doi.org/10.1176/appi.books.9780890425596
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Liepmann, D., Beauducel, A., Brocke, B., & Nettelnstroth, W. (2012). IST-Screening. Intelligenz-Struktur-Test. Göttingen: Hogrefe.
World Health Organisation. (2016). International statistical classification of diseases and related health problems (10th ed.). https://icd.who.int/browse10/2016/en
World Health Organisation. (2019). International statistical classification of diseases and related health problems (11th ed.). https://icd.who.int