Differences in sensory processing of German vowels and physically matched non-speech sounds as revealed by the mismatch negativity (MMN) of the human event-related brain potential (ERP)

Evidence for a General Auditory Processing Deficit in Developmental Dyslexia From a Discrimination Paradigm Using Speech Versus Nonspeech Sounds Matched in Complexity

“…The approach of studying auditory perception using vowel stimuli is, however, not limited to vowels that are embedded in CVC syllables: Several studies used single vowels. These studies investigated speech perception in adults with dyslexia (Vandermosten et al, 2010) and children with dyslexia (Vandermosten et al, 2011) or automatic sensory processing of speech stimuli as indexed by the mismatch negativity with healthy adults (see, e.g., Christmann, Berti, Steinbrink, & Lachmann, 2014;Näätänen et al, 1997) and children with dyslexia (Bruder et al, 2011;Corbera, Escera, & Artigas, 2006;Csépe, Gyurkocza, & Osman-Sagi, 1998). In the present study, isolated vowels were used as well, as is explained in further detail in the Materials and Method section.…”

When speech enhances Spatial Musical Association of Response Codes: Joint spatial associations of pitch and timbre in nonmusicians

“…Is this difference in the results then a consequence of the different nature of the stimuli, that is, an instrumental vs. a language-related stimulus? A number of studies indicate that vocal sounds are processed differently in the brain:Perrodin, Kayser, Logothetis, and Petkov (2011), for example, found voice cells in the temporal lobes of primates;Vouloumanos and Werker (2007) demonstrated that human newborns recognize speech contrasted with non-speech analogues;Christmann, Berti, Steinbrink and Lachmann (2014) recently showed different…”

Earlier timbre processing of instrumental tones compared to equally complex spectrally rotated sounds as revealed by the mismatch negativity

“…1). The resulting stimuli show exactly the same range of frequencies and complexity as the unfiltered tones (see also [17,21]). The overtone series is eliminated by the rotation as the fundamental frequency is changed, therefore, the spectrally rotated sounds are perceived as noise-like.…”

“…Comparable to prior research, 2000 Hz was chosen as center frequency for the rotation, this means that all frequencies are mirrored at this frequency. In order to maintain the perceived naturalness of the tones, which could be affected by the usage of the low pass filter (for more details see [16,17,20]), we modified the procedure to create spectrally rotated stimuli with a complete spectrum. This was achieved by adding all frequencies above 4000 Hz of the tone to the spectrally rotated stimulus with Audition (Version: CS5.5, Adobe, Munich, Germany).…”

“…As mentioned above, if the proposed effective processing of musical sounds is due to pitch facilitation, the MMN elicited by harmonically rich sounds should differ from equally complex sounds lacking the harmonic structure. In order to create non-musical sounds with the same complexity as the tones, we chose a procedure that was originally introduced for speech research: spectral rotation [16][17][18]. If the middle frequency is chosen carefully, this means that the middle frequency must not be a harmonic of the original tone; the overtone series of the tone will be eliminated completely by this procedure.…”