Previous research on auditory training (AT) for children with developmental language disorder (DLD) has been limited by inconsistent methodologies, varying outcome measures and a lack of focus on long-term effects. In this study, we presented the first comprehensive systematic review dedicated to evaluating the effectiveness of AT interventions in this population. Our findings indicated that AT may have positive effects on auditory processing, speech perception and phonological working memory in children with DLD which can provide novel insights for early intervention strategies.

Developmental language disorder (DLD) is a persistent neurodevelopmental condition affecting 6–15% of children, characterized by deficits in language acquisition, understanding, production and use (Bishop et al., 2017; World Health Organization, 2021). Without treatment, DLD can significantly impact academic performance, social interactions and future life prospects (Andreou and Aslanoglou, 2022; Graham et al., 2020; Duff et al., 2022; Gough Kenyon et al., 2020), potentially extending into adulthood (Goh et al., 2021; Dubois et al., 2020; Winstanley et al., 2021). While early interventions are crucial (Frizelle et al., 2023), current language therapies show limited long-term efficacy (Fan et al., 2022). Research priorities focus on evidence-based interventions for individual speech, language and communication goals in DLD (Kulkarni et al., 2022).

At present, there is no unified consensus on the neurobiological mechanism of DLD, but there are many theories that attempt to explain its potential causes, such as auditory temporal processing deficit (Protopapas, 2014), structural brain abnormalities in genetic (Whelan et al., 2018), neuroplasticity deficit (Price and Duman, 2020), auditory processing disorder (Ross-Swain, 2018) attention and executive function (Veríssimo et al., 2022). Auditory temporal processing deficit theory has received widespread attention in explaining DLD, and it can provide a measurable and neurally based cognitive mechanism explanation for the speech recognition, grammatical comprehension and language expression difficulties of DLD (Foss-Feig et al., 2017). A study suggests that not all children with DLD have temporal processing deficits, and some children’s language disorders are not accompanied by a low level of auditory temporal processing ability (Zapparrata et al., 2023). However, in the important cognitive and neural framework for understanding and intervening in DLD, temporal processing deficit theory can provide a theoretical framework to explain the neural mechanism-language symptoms-intervention path (Moll et al., 2016).

Auditory temporal processing deficit theory posits that children with DLD have difficulty processing rapidly unfolding auditory events, which affects their ability to discriminate speech (Szelag et al., 2015). The temporal sampling framework in the auditory temporal processing deficit theory links DLD to deficits in rise time perception and the ability to discriminate amplitude modulated sounds. The theory posits that children with DLD have difficulty perceiving and processing amplitude modulation signals, especially rhythms in the low frequency range (e.g., 2–50 Hz) (Goswami et al., 2016; Fraser et al., 2010; Martínez-Castilla et al., 2023).

In addition to the rise time perception and amplitude modulation discrimination disorders of the time sampling framework, DLD is also associated with other auditory processing (AP) defects, such as audition discrimination deficit, audition sequencing defects, auditory working/short-term memory defects and abnormal dichotic Listening (de Wit et al., 2018; Jones et al., 2024) AP mainly involves the perceptual processing of auditory information in the central auditory nervous system (CANS) which generates electrophysiological auditory potentials through neurobiological activities (ASHA, 2005). A study comparing the language abilities of children with DLD and normal children of the same age found that children with DLD performed poorly in speech recognition and speech contrast tasks, indicating that children with DLD have difficulty distinguishing phonemes which hinders the acquisition of phonological rules (Ziegler et al., 2005). Moreover, many studies have shown that DLD children perform poorly compared to children of the same age in perceiving and remembering the sequence of a series of sounds, maintaining and manipulating speech information, understanding speech in incomplete or disrupted situations, integrating information from the left and right ears into a unified perception (Blom and Boerma, 2020; Moran, 2022; Singer et al., 2023).

Given that children with DLD may have defects in AP, researchers have begun to try to use auditory training (AT) as an intervention to improve their language function (Rinaldi et al., 2021). Studies have shown that AT can improve speech recognition, auditory memory and language fluency in certain groups of language disorders, especially the phonological awareness and speech recognition ability of children with DLD (Chermak and Musiek, 2013). Since children with DLD show high heterogeneity in auditory processing, it is very important to choose the appropriate AT intervention method. There are currently two main methods for AT intervention. Current studies mostly use non-linguistic auditory stimuli (such as pure tones and frequency changes) or speech elements without semantic load (such as meaningless syllables) as training materials to isolate the influence of language processing and focus on the underlying perceptual mechanism (McArthur et al., 2008). However, some studies think that incorporating language components into the training paradigm can improve its ecological validity and better translate into benefits in real language use scenarios (Fey et al., 2011).

Many studies have applied AT to treat children with DLD, but its therapeutic effect has always been controversial. A comprehensive review by Murphy and Schochat (2013) analyzed the effects of various types of auditory timing training on language skills (Murphy and Schochat, 2013). The study found that AT has potential benefits for certain language skills, but further research is needed for the DLD population. Although this study analyzed the effects of AT on disorders related to language difficulties, there are relatively few studies on the effects of AT on the DLD population. Therefore, this study evaluated the intervention effects of two AT intervention models on DLD children by synthesizing existing research, which provides a theoretical basis for further understanding the potential mechanisms of DLD and formulating more targeted intervention strategies.

We reported the findings The findings are reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (Page et al., 2021). The protocol for this systematic review was registered with PROSPERO, registration number CRD42024583480.

This systematic review aimed to investigate the effects of AT on children diagnosed with DLD. Our analysis of nine studies (Eight RCTs and one quasi-experimental study) revealed mixed results regarding the efficacy of AT for this population. The inconsistent findings across various domains of language and auditory processing underscore the heterogeneous nature of DLD and the challenges in developing universally effective interventions.

Murphy and Schochat’s study mainly explored the potential promotion of three types of auditory time training (software-assisted training, formal auditory training, and music training) on children’s language ability (Murphy and Schochat, 2013). The evaluation index mainly focused on language skills themselves. This review specifically evaluates the effect of auditory training in children with DLD, including five aspects: language ability, speech perception, auditory behavior, electrophysiological response, and speech working memory. The results showed that although the training did not significantly improve core language skills, it may have a positive effect in improving phonetic awareness and certain auditory processing abilities.

Our review found limited evidence for the efficacy of AT in improving core language skills in children with DLD. Five studies consistently reported no significant improvements in various aspects of language abilities following AT interventions (Bishop et al., 2006; Cohen et al., 2005; Collet et al., 2012; Fey et al., 2010; Gillam et al., 2008). This finding contrasts with previous research on aphasia, which has demonstrated neuronal reorganization and enhanced synaptic activity in language-related brain areas following AT (Woodhead et al., 2017). For individuals with more severe conditions, enhanced interhemispheric transfer of information was observed between higher levels of the auditory cortex. However, our findings diverge from previous studies. This discrepancy may be attributed to the heterogeneous nature and broad spectrum of clinical symptoms within the DLD population (Toppelberg and Shapiro, 2000), suggesting that auditory processing deficits alone may not fully account for the language impairments observed in this population. Another limitation is that existing research on the efficacy of AT for language skills in children with DLD focuses predominantly on school-aged children (4–13 years in our included studies), thereby missing the timeframe of peak brain plasticity (Cardon et al., 2012). This could explain the lackluster impact of AT on language outcomes. Furthermore, three of the included studies employed the FFW-L program for their training modules (Cohen et al., 2005; Fey et al., 2010; Gillam et al., 2008). Meta-analyses from 2011 suggest that FFW-L does not yield significant benefits in any measured outcomes, such as single-word reading, passage reading comprehension, receptive language, and expressive language, when compared to active or untreated control groups (Strong et al., 2011). This factor may also have influenced the outcomes of our review, indicating a need for future studies to employ a broader range of AT approaches to fully explore language outcomes in DLD.

Despite the limited impact on overall language abilities, our review found more promising results in specific domains. For speech perception, five of the studies included in this review investigated the topic of speech perception, with four demonstrating significant improvements in speech perception skills following AT. This aligns with prior research indicating that individuals in the DLD group consistently underperform across various aspects of phonological awareness (Lara-Díaz et al., 2021). The improvements observed in speech perception suggest that AT may have potential benefits for foundational language skills, even if these improvements do not immediately translate to broader language abilities. For phonological awareness, our review revealed inconsistent results with previous research, which has established that phonetic awareness skills are strong predictors of future reading capabilities in children (Song et al., 2019). Therefore, early AT is anticipated to bolster the phonological awareness of children with DLD, consequently mitigating the risk of developing dyslexia.

For auditory processing measures, our review revealed inconsistent results. Two studies utilizing FFW-L and modified speech training did not demonstrate significant improvements in auditory behavioral tasks. These findings cast doubt on the claims that FFW-L could effectively address rapid auditory processing deficits in children with language impairment (Corporation, 1999). Additionally, the data provided little support for the effectiveness of modified speech training, and no correlation was observed between the number of training sessions and outcomes. However, two other studies in the review demonstrated that AT significantly improved temporal sequencing ability, figure-ground assessment, and auditory temporal thresholds. These results align well with previous research, suggesting that AT is effective in ameliorating auditory processing deficits (Loo et al., 2016). Future research in this field should focus on designing appropriate training regimens to further investigate whether enhancements in auditory processing skills can lead to corresponding improvements in language abilities.

In the studies included in this systematic review, the dosage of AT varied significantly, the duration of training ranged from a few weeks to several months, the duration of a single training session ranged from 30 min to 2 h, and the frequency of training ranged from twice a week to every day. This high heterogeneity may explain the inconsistency of the research results to some extent. Some studies have found that high-frequency and long-duration interventions are more effective in improving phonological awareness, while no significant changes were observed with lower-dose training (Harvey, 2022; Deng et al., 2024). However, some studies have not observed significant improvements in core language abilities even with higher-dose interventions, indicating that the dosage of AT is not the only factor that determines the efficacy (Justice, 2018; Storkel et al., 2019). Some studies believe that the content of training, individual differences in children, and the stage of language development at the time of intervention are also very important for children with DLD (Eisenberg, 2014; Cummings et al., 2021).

Electrophysiological measures provided interesting insights into the potential neural mechanisms underlying AT’s effects. Two studies reported significant increases in the amplitudes of MMN, P3, and c-ABR following AT. These findings suggest that AT may induce neurophysiological changes, even in the absence of clear behavioral improvements. This aligns with prior research utilizing magnetic resonance imaging (MRI) to evaluate brain plasticity following auditory cognitive training in older individuals has also supported these observations (Kawata et al., 2022). Specifically, the auditory cognitive training group exhibited improvements in pure-tone audiometry and showed increases in both regional gray matter volume and functional connectivity (FC) within the left temporal pole, in comparison to a control group not undergoing auditory cognitive training (Kawata et al., 2022). These results lend credence to the notion that AT may offer considerable benefits for neural function.

Previous findings have demonstrated that children with DLD exhibit poorer verbal and non-verbal working memory performance is poorer in children with DLD compared to their TD counterparts (Larson and Ellis Weismer, 2022). Our review examined two studies that investigating the effects of AT on phonological working memory, revealing inconsistent outcomes. While the FFW-L intervention did not lead to a significant enhancement in phonological working memory in school-aged children, research by Roden et al. demonstrated significant improvements in performance on the digit span, non-word recall, and recall of sentences tests, when compared to a control group. These results align with earlier work indicating that typically developing children can improve their auditory working memory through music training (Lee et al., 2007; Roden et al., 2014). The current study adds to this literature by suggesting that AT may also benefit the phonological short-term memory and phonological coding strategies for written words in children with DLD. One explanation for the discrepancy between the two studies could be the age of the participants during the intervention.

The age range of children is a key factor in designing AT, and the neurodevelopment of the central auditory system varies significantly at different ages (Chermak and Musiek, 2002). Early neuroplasticity provides a favorable time window for intervention, but young children have limited abilities in attention, self-regulation and task execution which may affect the realization of training effects. In addition, children of different ages also differ in the use of auditory processing strategies and cognitive resources (Herzberg et al., 2025). Although some studies have shown that the efficacy of AT for children with DLD is limited, there is evidence that AT may bring positive intervention effects in a variety of communication disorders, such as speech perception disorders, SLI and auditory processing disorders (Harvey, 2022; Deng et al., 2024).

The preschool years are associated with greater brain plasticity compared to the school-age years. This is especially pertinent when considering that deficits in phonological working memory often persist in children with delayed language development, even after receiving successful speech therapy (McGonigle-Chalmers and Kusel, 2019). Therefore, it is necessary to comprehensively consider the developmental stage and individual differences of children to optimize the training effect and enhance language-related functions in clinical applications.

The current review has several limitations that warrant discussion. First, despite our comprehensive search strategy, which included six major databases and additional manual searching, we only included articles published in English. This language restriction may have introduced a potential bias, as relevant studies published in other languages could have been overlooked. However, given the rigorous nature of our review process and the consistency of our findings across the included studies, the main conclusions of our study would not significantly change even if non-English publications were included. Second, many of the studies were conducted at single centers and featured small sample sizes. In particular, some studies included fewer than ten DLD cases. Second, many of the studies were conducted at single centers and featured small sample sizes. In particular, some studies included fewer than ten DLD cases (Collet et al., 2012; Fey et al., 2010; Filippini et al., 2012), which could compromise the reliability of the overall findings. Lastly, the overall methodological quality of the included studies was suboptimal, Our risk of bias assessment revealed that out of the eight RCTs, only two were assessed as having a low overall risk of bias, while six had some concerns. The quasi-experimental study included in our review was determined to have a serious risk of bias. Fast ForWord is a multifaceted intervention rather than a strictly defined auditory training (AT) approach. FFW combines auditory, language, and cognitive training modules, so the improvements observed in the study cannot be clearly attributed to auditory training alone, but may also be the result of language or cognitive training. These methodological limitations underscore the need for higher-quality research with more rigorous study designs to robustly assess the effects of AT on children with DLD.

This systematic review investigates the effects of AT for children with DLD, suggesting limited efficacy in improving overall language abilities, but demonstrates potential in enhancing specific skills like speech perception and phonological awareness. Electrophysiological evidence suggests possible neurophysiological changes. The heterogeneous outcomes underscore DLD’s complexity and the need for individualized interventions. Clinically, AT should be considered as an adjunctive treatment. Future research should focus on large-scale studies with standardized protocols, examining long-term outcomes and efficacy across diverse linguistic contexts, to develop evidence-based interventions for DLD.