Reduced auditory efferent activity in childhood selective mutism.
BACKGROUND
Selective mutism is a psychiatric disorder of childhood characterized by consistent inability to speak in specific situations despite the ability to speak normally in others. The objective of this study was to test whether reduced auditory efferent activity, which may have direct bearings on speaking behavior, is compromised in selectively mute children.


METHODS
Participants were 16 children with selective mutism and 16 normally developing control children matched for age and gender. All children were tested for pure-tone audiometry, speech reception thresholds, speech discrimination, middle-ear acoustic reflex thresholds and decay function, transient evoked otoacoustic emission, suppression of transient evoked otoacoustic emission, and auditory brainstem response.


RESULTS
Compared with control children, selectively mute children displayed specific deficiencies in auditory efferent activity. These aberrations in efferent activity appear along with normal pure-tone and speech audiometry and normal brainstem transmission as indicated by auditory brainstem response latencies.


CONCLUSIONS
The diminished auditory efferent activity detected in some children with SM may result in desensitization of their auditory pathways by self-vocalization and in reduced control of masking and distortion of incoming speech sounds. These children may gradually learn to restrict vocalization to the minimal amount possible in contexts that require complex auditory processing.
Bar-Haim
Yair
Y
Department of Psychology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Henkin
Yael
Y
Ari-Even-Roth
Daphne
D
Tetin-Schneider
Simona
S
Hildesheimer
Minka
M
Muchnik
Chava
C
D000158:Acoustic Impedance Tests / Q000379:methods; D000161:Acoustic Stimulation / Q000379:methods; D000293:Adolescent; D001301:Audiometry, Pure-Tone / Q000379:methods; D001306:Auditory Pathways / Q000503:physiopathology*; D001307:Auditory Perception / Q000502:physiology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D009155:Mutism / Q000503:physiopathology*; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology; D012022:Reflex, Acoustic / Q000502:physiology*; D013069:Speech Reception Threshold Test / Q000379:methods