Neurometric amplitude-modulation detection threshold measured in the chinchilla ventral cochlear nucleus following sensorineural hearing loss

2014 ◽  
Vol 135 (4) ◽  
pp. 2412-2412
Author(s):  
Mark Sayles ◽  
Ann E. Hickox ◽  
Michael G. Heinz
Author(s):  
Jawahar Antony P ◽  
Animesh Barman

Background and Aim: Auditory stream segre­gation is a phenomenon that splits sounds into different streams. The temporal cues that contri­bute for stream segregation have been previ­ously studied in normal hearing people. In peo­ple with sensorineural hearing loss (SNHL), the cues for temporal envelope coding is not usually affected, while the temporal fine structure cues are affected. These two temporal cues depend on the amplitude modulation frequency. The present study aimed to evaluate the effect of sin­usoidal amplitude modulated (SAM) broadband noises on stream segregation in individuals with SNHL. Methods: Thirty normal hearing subjects and 30 subjects with mild to moderate bilateral SNHL participated in the study. Two experi­ments were performed; in the first experiment, the AB sequence of broadband SAM stimuli was presented, while in the second experiment, only B sequence was presented. A low (16 Hz) and a high (256 kHz) standard modulation fre­quency were used in these experiments. The subjects were asked to find the irregularities in the rhythmic sequence. Results: Both the study groups could identify the irregularities similarly in both the experi­ments. The minimum cumulative delay was sli­ghtly higher in the SNHL group. Conclusion: It is suggested that the temporal cues provided by the broadband SAM noises for low and high standard modulation frequencies were not used for stream segregation by either normal hearing subjects or those with SNHL. Keywords: Stream segregation; sinusoidal amplitude modulation; sensorineural hearing loss


2021 ◽  
Vol 25 ◽  
pp. 233121652110146
Author(s):  
Nicholas L. Deep ◽  
Patricia L. Purcell ◽  
Karen A. Gordon ◽  
Blake C. Papsin ◽  
J. Thomas Roland Jr. ◽  
...  

The aim of this study was to investigate surgical, anesthetic, and device-related complications associated with cochlear implantation (CI) in children younger than 1 year of age. This was a multicenter, retrospective chart review of all children with severe-to-profound sensorineural hearing loss who underwent cochlear implantation with a Cochlear Nucleus Implant System before 1 year of age. Endpoints included perioperative course, major and minor surgical, anesthetic and device-related complications, and 30-day readmission rates. One hundred thirty-six infants (242 ears) met criteria. The mean age at implantation was 9.4 months (standard deviation 1.8). Six-month follow-up was reported in all patients. There were no major anesthetic or device-related complications. Adverse events were reported in 34 of implanted ears (14%; 7 major, 27 minor). Sixteen adverse events occurred ≤30 days of surgery, and 18 occurred >30 days of surgery. The 30-day readmission rate was 1.5%. The rate of adverse events did not correlate with preexisting medical comorbidities or duration under anesthesia. There was no significant difference detected in complication rate for patients younger than 9 months of age versus those 9 to 11 months of age. This study demonstrates the safety of CI surgery in infants and supports reducing the indication for cochlear implantation to younger than 1 year of age for children with bilateral, profound sensorineural hearing loss obtaining a Cochlear Nucleus Implant System.


1992 ◽  
Vol 35 (6) ◽  
pp. 1410-1421 ◽  
Author(s):  
Gail A. Takahashi ◽  
Sid P. Bacon

Temporal processing of suprathreshold sounds was examined in a group of young normalhearing subjects (mean age of 26.0 years), and in three groups of older subjects (mean ages of 54.3, 64.8, and 72.2 years) with normal hearing or mild sensorineural hearing loss. Three experiments were performed. In the first experiment (modulation detection), subjects were asked to detect sinusoidal amplitude modulation (SAM) of a broadband noise, for modulation frequencies ranging from 2–1024 Hz. In the second experiment (modulation masking), the task was to detect a SAM signal (modulation frequency of 8 Hz) in the presence of a 100%-modulated SAM masker. Masker modulation frequency ranged from 2–64 Hz. In the final experiment, speech understanding was measured as a function of signal-to-noise ratio in both an unmodulated background noise and in a SAM background noise that had a modulation frequency of 8 Hz and a modulation depth of 100%. Except for a very modest correlation between age and modulation detection sensitivity at low modulation frequencies, there were no significant effects of age once the effect of hearing loss was taken into account. The results of the experiments suggest, however, that subjects with even a mild sensorineural hearing loss may have difficulty with a modulation masking task, and may not understand speech as well as normal-hearing subjects do in a modulated noise background.


1989 ◽  
Vol 98 (5) ◽  
pp. 326-331 ◽  
Author(s):  
Pierre Bonfils ◽  
Alain Uziel

Click-evoked otoacoustic emissions were recorded in a group of normally hearing subjects (n = 52 ears) and a group of patients demonstrating several common types of sensorineural hearing loss (n = 85 ears) in order to study the clinical applicability of acoustic emissions. In the normally hearing population, all ears demonstrated acoustic emissions that could be elicited at intensities below the normal subjective threshold for the sequence of clicks (mean, −5.2 dB hearing level [HL]). Sixty-seven percent of the normal ears showed long (>20 ms) click-evoked emissions, and spectral analysis showed a broadband spectral component with several narrowband frequency peaks. In patients with sensorineural hearing loss, the incidence of acoustic emissions decreased and the detection threshold increased linearly with increasing threshold. No emissions were elicited from ears exhibiting subjective click thresholds >35 dB HL. Hearing-impaired ears showed a significantly higher proportion of short duration emissions and a significant reduction in the mean number of narrowband frequency peaks in comparison to the controls. Therefore, acoustic emissions can be used as a reliable technique for objective study of normal micromechanical activity within the cochlea and for detection of subtle changes in cochlear disease. However, they have not been demonstrated to be useful in differentiating cochlear disease.


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