title: Optimizing swept-tone protocols for recording distortion-product otoacoustic emissions in adults and newborns.
abstract: Distortion-product otoacoustic emissions (DPOAEs), which are routinely used in the audiology clinic and research laboratory, are conventionally recorded with discrete tones presented sequentially across frequency. However, a more efficient technique sweeps tones smoothly across frequency and applies a least-squares-fitting (LSF) procedure to compute estimates of otoacoustic emission phase and amplitude. In this study, the optimal parameters (i.e., sweep rate and duration of the LSF analysis window) required to record and analyze swept-tone DPOAEs were tested and defined in 15 adults and 10 newborns. Results indicate that optimal recording of swept-tone DPOAEs requires use of an appropriate analysis bandwidth, defined as the range of frequencies included in each least squares fit model. To achieve this, the rate at which the tones are swept and the length of the LSF analysis window must be carefully considered and changed in concert. Additionally, the optimal analysis bandwidth must be adjusted to accommodate frequency-dependent latency shifts in the reflection-component of the DPOAE. Parametric guidelines established here are equally applicable to adults and newborns. However, elevated noise during newborn swept-tone DPOAE recordings warrants protocol adaptations to improve signal-to-noise ratio and response quality.
authors.affiliation: Keck School of Medicine, University of Southern California, Caruso Department of Otolaryngology, 1540 Alcazar Street, Los Angeles, California 90033, USA.
authors.forename: Carolina
authors.initials: C
authors.lastname: Abdala
authors.affiliation: Keck School of Medicine, University of Southern California, Caruso Department of Otolaryngology, 1540 Alcazar Street, Los Angeles, California 90033, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Luo
authors.affiliation: Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, Massachusetts 02114, USA.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Shera
mesh_terms: D000161:Acoustic Stimulation; D000162:Acoustics; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001301:Audiometry, Pure-Tone; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D015997:Neonatal Screening / Q000379:methods*; D017084:Otoacoustic Emissions, Spontaneous; D013018:Sound Spectrography; D013997:Time Factors; D055815:Young Adult