The HypoVoice study aims at identifying potential vocal biomarkers associated with hypoglycemia to pave the way towards a voice-based hypoglycemia detection approach.

While hypoglycemia has been widely studied in medical research, studies assessing vocal changes associated with this state are limited. This study aims at collecting a data set labelled with the gold standard (blood glucose) to provide a solid basis for the identification of vocal biomarkers using machine learning. Additionally, physiological data are collected using wearable sensors to assess whether additional integration of vital signs (e.g. heart rate) enhances the performance of hypoglycemia detection.

Inclusion Criteria:

• Written informed consent
• Type 1 Diabetes mellitus as defined by WHO for at least 6 months
• Aged 18 - 60 years
• HbA1c ≤9.0 %
• Functional insulin treatment with good knowledge of insulin self-management
• Native language German or Swiss German
• Use of continuous glucose monitoring (CGM) or flash glucose monitoring (FGM)

Exclusion Criteria:

• Incapacity to give informed consent
• Contraindications to insulin aspart (NovoRapid®)
• Total daily insulin dose >2 IU/kg/day
• Pregnancy, breast-feeding or lack of safe contraception
• Active heart, lung, liver, gastrointestinal, renal or psychiatric disease
• Pacemaker or implantable cardioverter defibrillator (ICD)
• Epilepsy or history of seizure
• Chronic neurological or ear-nose-and-throat (ENT) disease influencing voice or history of voice disorder
• Illiteracy or dyslexia
• Active smoking
• Active drug or alcohol abuse
• Medication known to interfere with voice or to induce listlessness (e.g. opioids, benzodiazepines, etc.)

Participants are aware that hypoglycemia will be induced during the study but they are blinded to their blood glucose levels throughout the hypoglycemia procedure.