[Judgement of disproportionate loss between Mandarin monosyllable discrimination and pure tone hearing thresholds].
OBJECTIVE
To establish the criteria of the disproportionate loss of Mandarin monosyllable discriminative abilities to pure tone hearing thresholds.


METHODS
Total of 165 patients with varying degrees of sensorineural hearing loss were recruited for routine audiological evaluations. The speech discrimination scores were obtained by Mandarin phonemic-balanced monosyllable lists via self-made speech audiometric software. The Performance-Intensity (P-I) function for individual ear was obtained by the same list which was administrated in ascending intensities, with 25 monosyllables presenting randomly. The lowest intensity was determined by the lowest pure tone threshold among all audiometric frequencies minus 5 dB. The intensities were increased in 5 dB step until the score was 100% or the intensity was reached to the patient's uncomfortable level. The PB(max) was obtained from the P-I plot. Three parameters about pure tone average hearing thresholds, including PTA(1) (average of 0.5, 1 and 2 kHz), PTA(2) (average of 1, 2 and 4 kHz) and PTA(3) (average of 0.5, 1, 2 and 4 kHz), as well as three parameters about audiogram slope, including Slope(0.5) (4 kHz minus 0.5 kHz), Slope(1) (4 kHz minus 1 kHz) and Slope(2) (4 kHz minus 2 kHz), were calculated respectively. The correlations between PB(max) and above parameters were analyzed by SPSS10.0 statistical software.


RESULTS
The audiogram slopes were not shown any correlation with PB(max), while the pure tone average thresholds, especially PTA(3) (r = -0.595, P = 0.000) were confirmed to correlate with PB(max). In the scatter plot based on PB(max) and PTA(3), a linear boundary was constructed encompassing approximately 99% of observed data collected from the sensorineural hearing-impaired.


CONCLUSIONS
Any PB(max) score falling below the boundary should be considered with high possibility and disproportionately poor comparison with pure tone hearing thresholds.
Department of Otorhinolaryngology Head and Neck Surgery, General Hospital of People's Liberation Army, Beijing 100853, China.
Jian-hui
JH
Li
Xin
X
Xi
Yang
Y
Zhao
Fei
F
Ji
Ai-ting
AT
Chen
Wei-yan
WY
Yang
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001301:Audiometry, Pure-Tone; D001302:Audiometry, Speech; D001309:Auditory Threshold; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult