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Behavioral Assessment of Hearing in 2 to 4 Year-old Children: A Two-interval, Observer-based Procedure Using Conditioned Play-based Responses
Published on: January 23, 2017
Spontaneous otoacoustic emissions in two infants
Kimitaka Kaga1, Yusuke Akamatsu, Masako Nakamura
1National Institute of Sensory Organs, National Tokyo Medical Center, Tokyo. kimikaga-tky@umin.ac.jp
Insights
Audible spontaneous otoacoustic emissions (SOAEs) were observed in two infants, characterized by continuous sounds originating from their ears. These unique SOAEs persisted as the infants developed, suggesting infantile outer hair cell hyperactivity.
Area of Science:
- Otoacoustic emissions research
- Pediatric audiology
- Auditory system development
Background:
- Spontaneous otoacoustic emissions (SOAEs) are typically not audible to humans.
- Infantile SOAEs are rare and their characteristics require further investigation.
Observation:
- Two infants presented with audible continuous sounds emanating from their ears, perceived by their parents.
- Audiological examinations, including distortion-product otoacoustic emissions (DPOAEs) and auditory brainstem responses (ABRs), were performed.
- Frequency analysis identified SOAEs at 4.2, 6.5, and 6.7 kHz for the two patients.
Findings:
- The infants exhibited normal DPOAEs and ABRs, indicating healthy cochlear function.
- The audible sounds were objectively diagnosed as SOAEs.
- These infantile SOAEs persisted over a two-year follow-up period, showing no signs of disappearance with development.
Implications:
- The persistent, audible SOAEs in these infants suggest a unique phenomenon possibly linked to spontaneous outer hair cell hyperactivity during early development.
- This case series highlights the potential for SOAEs to manifest audibly in infants and provides valuable data for understanding their developmental trajectory.
- Further research into the mechanisms and long-term implications of infantile SOAEs is warranted.
Conclusion:
We regard spontaneous otoacoustic emission (SOAE) as a unique phenomenon due to spontaneous outer hair cell hyperactivity during the infantile period in these two infants.
Objectives:
We report the cases of SOAEs in two infants, which were audible to their parents. We were able to hear continuous sounds from these two infants' ears. We studied their hearing and the emitted sounds objectively.
Patients And Methods:
Patient 1 was a 5-month-old girl and patient 2 was an 11-month-old girl. Their parents heard continuous sounds emanating from their infants' ears. Audiological examinations and frequency analysis were conducted.
Results:
The distortion-product otoacoustic emissions (DPOAEs) and auditory brainstem responses (ABRs) of the two patients were normal. Analysis of the continuous sounds demonstrated frequencies of 4.2 and 6.5 kHz for patient 1 and 6.7 kHz for patient 2. These audible sounds were diagnosed as SOAEs. The SOAEs in these infants did not disappear with their development in the last 2 years.
