Effects of Background Noise on Cortical Encoding of Speech in Autism Spectrum Disorders

Abstract

This study provides new evidence of deficient auditory cortical processing of speech in noise in autism spectrum disorders (ASD). Speech-evoked responses (~100-300 ms) in quiet and background noise were evaluated in typically-developing (TD) children and children with ASD. ASD responses showed delayed timing (both conditions) and reduced amplitudes (quiet) compared to TD responses. As expected, TD responses in noise were delayed and reduced compared to quiet responses. However, minimal quiet-to-noise response differences were found in children with ASD, presumably because quiet responses were already severely degraded. Moreover, ASD quiet responses resembled TD noise responses, implying that children with ASD process speech in quiet only as well as TD children do in background noise.

Fragile Spectral and Temporal Auditory Processing in Adolescents with Autism Spectrum Disorder and Early Language Delay

“…Interestingly, individual differences in temporal resolution were positively related to speech-in-noise perception in the ASD sample, which suggests that impaired temporal perception at the ms scale may impact upon speech and language learning, possibly through less optimal consonant discrimination (Bhatara et al 2013). This fits with findings of electrophysiological studies showing reduced automatic discrimination of consonants in ASD (e.g., Jansson-Verkasalo et al 2003;Kuhl et al 2005;Russo et al 2009). …”

A review of behavioural and electrophysiological studies on auditory processing and speech perception in autism spectrum disorders

“…No differences in MMN or N1 between participants with autism and controls were found, suggesting largely intact initial auditory cortical processing and discrimination of syllables. Kuhl et al (2005) found impaired syllable discrimination, in line with Jansson-Verkasalo et al (2003) and Russo et al (2009). However, Kuhl et al were able to associate their findings with a non-speech sound preference.…”

“…These studies mainly found evidence of impaired syllable discrimination (Jansson-Verkasalo et al, 2003;Kuhl et al, 2005;Russo et al, 2009), which seemed to be associated with a non-speech sound preference (Kuhl et al, 2005). Intact syllable discrimination in high functioning children with autism was found by Kemner et al (1995).…”

“…In a study by JanssonVerkasalo et al (2003) phonetic discrimination of syllables and initial auditory cortical processing of pure tones and syllables were impaired in children with Asperger syndrome, though the latter impairment was more severe for pure tones. In a study by Russo, Zecker, Trommer, Chen, and Kraus (2009) syllable processing was investigated in a quiet condition and in a condition with background noise. Children with ASD were less efficient than controls in their auditory cortical processing of syllables, with or without noise.…”

Age-Related Changes in the Relationship Between Auditory Brainstem Responses and Envelope-Following Responses

“…FFRs and EFRs are evoked in response to longer, often more spectro-temporally complex stimuli (Krishnan 1999(Krishnan , 2002Krishnan et al 2004;Swaminathan et al 2008), and are strongly influenced by rostral brainstem and midbrain generators (Kiren et al 1994;Kuwada et al 2002;Akhoun et al 2010;Chandrasekaran and Kraus 2010;Parthasarathy and Bartlett 2012). They have been used to show differences in processing of complex stimuli under various pathological conditions, such as age-related hearing loss, dyslexia, and autism (McAnally and Stein 1997;Chandrasekaran et al 2009;Russo et al 2009;Anderson et al 2012;Clinard and Tremblay 2013).…”