Distortion-product otoacoustic-emission suppression tuning in human infants and adults using absorbed sound power

Abstract

The greatest difference in distortion product otoacoustic emission (DPOAE) suppression tuning curves (STCs) in infant and adult ears occurs at a stimulus frequency of 6 kHz. These infant and adult STCs are much more similar when constructed using the absorbed power level of the stimulus and suppressor tones rather than using sound pressure level. This procedure incorporates age-related differences in forward and reverse transmission of sound power through the ear canal and middle ear. These results support the theory that the cochlear mechanics underlying DPOAE suppression are substantially mature in full-term infants.

Time–frequency analysis of linear and nonlinear otoacoustic emissions and removal of a short-latency stimulus artifact

“…Whether it can be used on newborns in a clinical setting is yet to be determined. Adults and newborns have different OAEs in terms of spectral content and prevalence of SOAEs (e.g., Keefe and Abdala, 2011), and the smaller ear canal of newborns may generate different artifacts.…”

Development of the auditory system

“…Nuanced research into this area further suggests that maturational changes occur particularly in the apical region of the cochlea, where low-frequency information is generally processed. How these maturational changes influence perceptual outcomes is yet to be understood (Keefe and Abdala, 2011). …”

Acoustical Tests of Middle-Ear and Cochlear Function in Infants and Adults

“…When the SPLs of the stimuli used to generate and suppress the DPOAE were used with age-dependent conductance measurements to calculate absorbed power, the resulting power-based suppression tuning curves shown in Fig. 6 were nearly identical for full-term infants, six-month-olds and adults (Keefe and Abdala, 2011).…”

“…This and other adult reflectance measurements (Voss and Allen, 1994) straddled the low frequencies used in clinical tympanometry and the high frequencies used in OAEs. An aural acoustic transfer function well suited to clinical use is acoustic absorbance, which is the Keefe and Abdala (2011)] ratio of the sound energy absorbed by the ear to the incident energy from a transient sound. The absorbance, which is equal to 1-|R(f)| 2 , is insensitive to probe position within the ear canal.…”

“…An ABR test is more time consuming and costly than an OAE test. Nevertheless, the ABR test is recommended by JCIH for NICU babies because they are at higher risk for sensorineural hearing loss, and because neu- Keefe and Abdala (2011)] ral conduction disorders or auditory neuropathy/dyssynchrony in the absence of sensory dysfunction may not be detected by an OAE test.…”