Limits...
Outer Hair Cell and Auditory Nerve Function in Speech Recognition in Quiet and in Background Noise

View Article: PubMed Central - PubMed

ABSTRACT

The goal of this study was to describe the contribution of outer hair cells (OHCs) and the auditory nerve (AN) to speech understanding in quiet and in the presence of background noise. Fifty-three human subjects with hearing ranging from normal to moderate sensorineural hearing loss were assayed for both speech in quiet (Word Recognition) and speech in noise (QuickSIN test) performance. Their scores were correlated with OHC function as assessed via distortion product otoacoustic emissions, and AN function as measured by amplitude, latency, and threshold of the VIIIth cranial nerve Compound Action Potential (CAP) recorded during electrocochleography (ECochG). Speech and ECochG stimuli were presented at equivalent sensation levels in order to control for the degree of hearing sensitivity across patients. The results indicated that (1) OHC dysfunction was evident in the lower range of normal audiometric thresholds, which demonstrates that OHC damage can produce “Hidden Hearing Loss,” (2) AN dysfunction was evident beginning at mild levels of hearing loss, (3) when controlled for normal OHC function, persons exhibiting either high or low ECochG amplitudes exhibited no statistically significant differences in neither speech in quiet nor speech in noise performance, (4) speech in noise performance was correlated with OHC function, (5) hearing impaired subjects with OHC dysfunction exhibited better speech in quiet performance at or near threshold when stimuli were presented at equivalent sensation levels. These results show that OHC dysfunction contributes to hidden hearing loss, OHC function is required for optimum speech in noise performance, and those persons with sensorineural hearing loss exhibit better word discrimination in quiet at or near their audiometric thresholds than normal listeners.

No MeSH data available.


SIQ at or near threshold is correlated with OHC function. Distribution of WRSs in quiet from all subjects presented at 0 dB SL as a function of DPAOE amplitude (A) and DPAOE threshold (B) at 4 k Hz; as well as AN function measured by CAP amplitude (C), and latency (D) in response to 4 kHz tone pips presented at 40 dB SL, and CAP thresholds (E). Lines represent best fit (linear).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5383716&req=5

Figure 10: SIQ at or near threshold is correlated with OHC function. Distribution of WRSs in quiet from all subjects presented at 0 dB SL as a function of DPAOE amplitude (A) and DPAOE threshold (B) at 4 k Hz; as well as AN function measured by CAP amplitude (C), and latency (D) in response to 4 kHz tone pips presented at 40 dB SL, and CAP thresholds (E). Lines represent best fit (linear).

Mentions: In order to examine whether OHC and or AN function played a role in speech recognition in quiet, subjects were presented NU-6 word lists at equivalent SLs and the subjects' WRSs were correlated with OHC and AN function. The results showed that presentation Levels between 10 and 40 dB SL failed to yield clinically significant differences in any metric (data not shown). However, WRS presented at or near threshold was correlated with OHC function (Figure 10).


Outer Hair Cell and Auditory Nerve Function in Speech Recognition in Quiet and in Background Noise
SIQ at or near threshold is correlated with OHC function. Distribution of WRSs in quiet from all subjects presented at 0 dB SL as a function of DPAOE amplitude (A) and DPAOE threshold (B) at 4 k Hz; as well as AN function measured by CAP amplitude (C), and latency (D) in response to 4 kHz tone pips presented at 40 dB SL, and CAP thresholds (E). Lines represent best fit (linear).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5383716&req=5

Figure 10: SIQ at or near threshold is correlated with OHC function. Distribution of WRSs in quiet from all subjects presented at 0 dB SL as a function of DPAOE amplitude (A) and DPAOE threshold (B) at 4 k Hz; as well as AN function measured by CAP amplitude (C), and latency (D) in response to 4 kHz tone pips presented at 40 dB SL, and CAP thresholds (E). Lines represent best fit (linear).
Mentions: In order to examine whether OHC and or AN function played a role in speech recognition in quiet, subjects were presented NU-6 word lists at equivalent SLs and the subjects' WRSs were correlated with OHC and AN function. The results showed that presentation Levels between 10 and 40 dB SL failed to yield clinically significant differences in any metric (data not shown). However, WRS presented at or near threshold was correlated with OHC function (Figure 10).

View Article: PubMed Central - PubMed

ABSTRACT

The goal of this study was to describe the contribution of outer hair cells (OHCs) and the auditory nerve (AN) to speech understanding in quiet and in the presence of background noise. Fifty-three human subjects with hearing ranging from normal to moderate sensorineural hearing loss were assayed for both speech in quiet (Word Recognition) and speech in noise (QuickSIN test) performance. Their scores were correlated with OHC function as assessed via distortion product otoacoustic emissions, and AN function as measured by amplitude, latency, and threshold of the VIIIth cranial nerve Compound Action Potential (CAP) recorded during electrocochleography (ECochG). Speech and ECochG stimuli were presented at equivalent sensation levels in order to control for the degree of hearing sensitivity across patients. The results indicated that (1) OHC dysfunction was evident in the lower range of normal audiometric thresholds, which demonstrates that OHC damage can produce “Hidden Hearing Loss,” (2) AN dysfunction was evident beginning at mild levels of hearing loss, (3) when controlled for normal OHC function, persons exhibiting either high or low ECochG amplitudes exhibited no statistically significant differences in neither speech in quiet nor speech in noise performance, (4) speech in noise performance was correlated with OHC function, (5) hearing impaired subjects with OHC dysfunction exhibited better speech in quiet performance at or near threshold when stimuli were presented at equivalent sensation levels. These results show that OHC dysfunction contributes to hidden hearing loss, OHC function is required for optimum speech in noise performance, and those persons with sensorineural hearing loss exhibit better word discrimination in quiet at or near their audiometric thresholds than normal listeners.

No MeSH data available.