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Updated: Nov 4, 2025
Infant Auditory Processing and Event-related Brain Oscillations
Published on: July 1, 2015
Frequency-Following Response in Newborns and Infants: A Systematic Review of Acquisition Parameters
Fabiana Aparecida Lemos1,2, Aryelly Dayane da Silva Nunes1,2, Carolina Karla de Souza Evangelista1,2
1Speech, Language and Hearing Sciences Graduate Program, Health Sciences Center, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil.
Insights
This systematic review found consensus on some frequency-following response (FFR) acquisition parameters for infants, like using the /da/ syllable. However, no single established protocol exists for FFR testing in children up to 24 months.
Area of Science:
- Neuroscience
- Audiology
- Developmental Psychology
Background:
- The frequency-following response (FFR) is a neurophysiological measure reflecting auditory processing.
- Understanding FFR acquisition parameters in infants is crucial for accurate auditory assessment.
- Previous research indicates variability in FFR testing methodologies.
Purpose of the Study:
- To systematically review and characterize parameters used for frequency-following response (FFR) acquisition in children up to 24 months of age.
- To identify consensus and variability in FFR testing protocols for infants.
- To inform the development of standardized FFR assessment procedures.
Main Methods:
- Systematic review registered in PROSPERO, adhering to PRISMA guidelines.
- Comprehensive search of multiple databases and gray literature, supplemented by manual searches.
- Inclusion of observational studies using speech stimuli in normally hearing infants aged 0-24 months; risk of bias assessment performed.
Main Results:
- Fifteen articles were included from 459 identified studies, with varying risk of bias (7 low, 7 moderate, 1 high).
- Consensus was observed for specific parameters: vertical electrode mounting, alternating polarity, 20000 Hz sampling rate, and a 40 ms /da/ synthesized syllable stimulus.
- Significant variability exists in other parameters, including presentation rate, time window, number of sweeps, artifact rejection, and examination conditions.
Conclusions:
- While some parameters for speech-evoked FFR in infants show consensus, a universally established protocol is lacking.
- The identified consensus parameters provide a foundation for more consistent FFR acquisition in young children.
- Further standardization efforts are needed to ensure reliable and comparable FFR data in infant auditory research and clinical practice.
Abstract:
Purpose The purpose of this study is to characterize parameters used for frequency-following response (FFR) acquisition in children up to 24 months of age through a systematic review. Method The study was registered in PROSPERO and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses' recommendations. Search was performed in six databases (LILACS, LIVIVO, PsycINFO, PubMed, Scopus, and Web of Science) and gray literature (Google Scholar, OpenGrey, ProQuest)as well as via manual searches in bibliographic references. Observational studies using speech stimuli to elicit the FFR in infants with normal hearing on the age range from 0 until 24 months were included. No restrictions regarding language and year of publication were applied. Risk of bias was assessed with the Joanna Briggs Institute Critical Appraisal Checklist. Data on stimulus, presentation rate, time window for analysis, number of sweeps, artifact rejection, online filters, stimulated ear, and examination condition were extracted. Results Four hundred fifty-nine studies were identified. After removing duplicates and reading titles and abstracts, 15 articles were included. Seven studies were classified as low risk of bias, seven as moderate risk, and one as high risk. Conclusions There is a consensus in the use of some acquisition parameters of the FFR with speech stimulus, such as the vertical mounting, the use of alternating polarity, a sampling rate of 20000 Hz, and the /da/ synthesized syllable of 40 ms in duration as the preferred stimulus. Although these parameters show some consensus, the results disclosed lack of a single established protocol for FFR acquisition with speech stimulus in infants in the investigated age range.
