Childrens’ Phoneme Identification in Reverberation and Noise

Abstract

This study assessed the effects of reverberation, noise, and their combination on listeners' identification of consonants and vowels in naturally produced nonsense syllables presented at different sensation levels (re: speech recognition threshold). A secondary purpose of this study was to assess listeners' identification of voicing, manner, and place of articulation for consonants at 50 dB SL in the reverberation, noise, and combined conditions. Listeners, aged 6-30 years, identified consonant-vowel-consonant-vowel (CVCV) stimuli presented at four different sensation levels (re: speech recognition threshold) of 30, 40, 50, and 60 dB SL in 4 listening conditions: (a) an optimal listening situation (no reverberation, no noise), (b) reverberation only (1.3 seconds), (c) noise only (+13 dB S/N against a multitalker babble), and (d) reverberation plus noise. Results showed that all listener groups achieved maximum consonant identification performance at 50 dB SL. Vowel identification scores were unaffected by SL. Statistical analyses revealed that children's ability to identify consonants varied according to listening condition. For example, children's consonant identification abilities reached adult-like levels of performance at about age 14 years in the reverberation-only and noise-only listening conditions. However, in the reverberation-plus-noise listening condition, children's consonant identification abilities do not mature until the late teenage years. The ability to identify vowels, on the other hand, develops much earlier. A feature analysis of the consonant data showed that for all 3 features (voicing, manner, and place), identification scores were highest in the control condition, similar for the reverberation-only and noise-only conditions, and lowest in the reverberation-plus-noise condition. Voicing was easier for listeners to identify than manner or place of articulation features in reverberation and noise. Taken together, these results suggest that the ability to identify speech in reverberation and noise reaches adult-like level of performance at different ages for different components of the speech signal.

Issues in human auditory development

“…For example, Hazan and Barrett (2000) found that children were more consistent in identification when multiple cues were available compared to when only a single cue was available suggesting that children lack the flexibility to use whatever cue was available. Nittrouer et al (2000) came to a similar conclusion in a study of 5-and 7-year-old children, and Johnson's (2000) observation that even 15-year-olds performed more poorly than adults in speech identification in the presence of noise or reverberation also is consistent with this idea.…”

Impairments in speech and nonspeech sound categorization in children with dyslexia are driven by temporal processing difficulties

“…At the nonspeech level, this is in line with (1) physiological animal studies showing that neural coding for temporal aspects of the stimulus reaches maturity later than neural coding for frequency selectivity (Eggermont, 1996), and with (2) behavioral auditory studies in humans providing evidence for a more prolonged development of the sensitivity for temporal than for nontemporal auditory cues (Hartley, Wright, Hogan, & Moore, 2000), even after accounting for the effect of procedure-related skills (Dawes & Bishop, 2008). At the speech level, it coincides with behavioral speech perception studies demonstrating that the identification of stop consonants is not yet mature by the age of 11 (Hazan & Barrett, 2000;Johnson, 2000;Krause, 1982;Simon & Fourcin, 1978;Medina, Hoonhorst, Bogliotti, & Serniclaes, 2010), whereas the identification of vowels does only slightly, though not significantly, improves towards adolescence (Pursell, Swanson, Hedrick, & Nabelek, 2002;Ohde, Haley, & McMahon, 1996;Johnson, 2000, but see Walley and Flege, 1999). Further elaboration on this topic is needed, but the indication that perception of sounds with temporal versus nontemporal cues follows different maturational trajectories in both normal and dyslexic readers, may have practical implications with regard to auditory temporal training programs.…”

Speech Perception in Children Under Noisy Situations

“…A literatura indica que o reconhecimento de fala das crianças normo-ouvintes é mais afetado por condições adversas como no ruído e/ou em ambiente reverberante quando comparadas aos adultos e esse desempenho pior em crianças para percepção da fala no ruído é esperado até os dez ou doze anos de idade (13)(14)(15)(16)(17)(18)(19)(20)(21). Os estudos supracitados não utilizaram ruído difuso, como as quatro caixas de campo livre adotadas no presente trabalho.…”