This study introduces and validates a novel, discreet, and unobstructive in-ear sensing system for long-term electroencephalography (EEG) recording, specifically designed to detect focal-onset seizures. The ear-EEG device is a wearable, ear-bud-like system that captures EEG signals from the ear canal, which is anatomically close to the temporal lobe, a common site for focal seizures. The study compares the seizure detection utility of the ear-EEG system with that of intracranial EEG and scalp EEG in 20 patients with refractory focal epilepsy. The results show that two epileptologists were able to detect 86.4% of seizures using the ear-EEG signals, with a false detection rate of 0.1 per day, which is significantly lower than the rate reported for ambulatory monitoring. The device was well-tolerated by patients, with only minor adverse events reported. The study suggests that the ear-EEG device may assist clinicians in making an epilepsy diagnosis, assessing treatment efficacy, and optimizing medication titration. The ear-EEG system's ability to capture temporal lobe seizures with high sensitivity and its potential for integration with existing algorithms make it a promising tool for continuous monitoring of neurological activity outside traditional clinical settings.This study introduces and validates a novel, discreet, and unobstructive in-ear sensing system for long-term electroencephalography (EEG) recording, specifically designed to detect focal-onset seizures. The ear-EEG device is a wearable, ear-bud-like system that captures EEG signals from the ear canal, which is anatomically close to the temporal lobe, a common site for focal seizures. The study compares the seizure detection utility of the ear-EEG system with that of intracranial EEG and scalp EEG in 20 patients with refractory focal epilepsy. The results show that two epileptologists were able to detect 86.4% of seizures using the ear-EEG signals, with a false detection rate of 0.1 per day, which is significantly lower than the rate reported for ambulatory monitoring. The device was well-tolerated by patients, with only minor adverse events reported. The study suggests that the ear-EEG device may assist clinicians in making an epilepsy diagnosis, assessing treatment efficacy, and optimizing medication titration. The ear-EEG system's ability to capture temporal lobe seizures with high sensitivity and its potential for integration with existing algorithms make it a promising tool for continuous monitoring of neurological activity outside traditional clinical settings.