Sleep
Listen: snoring and pauses in breathing
If you think your partner's breathing stops, you can hear here what it sounds like. The clips were recorded in a sleep laboratory with a microphone above the bed. The dashed lines mark the moments experts scored in the sleep test done the same night.
Do not diagnose yourself from sound. Hearing similar sounds does not mean there is sleep apnea; not hearing them does not mean there is none. A diagnosis can only be made with a sleep test. When to see a doctor?
Quiet breathing
For comparison: breathing without snoring, regular and quiet. The sound is barely audible and the rhythm never breaks.
Spectrogram: time across, pitch (0 to 5 kHz) upwards. Lighter colour means stronger sound; dashed lines mark the boundaries of the event scored by an expert. For expertsevent, duration, recording conditions
Expert scoring: no respiratory event scored. Severity of sleep apnea in the person recorded: moderate. Amplified by +37 dB so it can be heard, with frequencies below 200 Hz filtered out.
Regular snoring
A sound repeated in the same tone with every breath. It can be loud, but the rhythm does not break and no long silences come in between. This kind of snoring is often harmless on its own.
Spectrogram: time across, pitch (0 to 5 kHz) upwards. Lighter colour means stronger sound; dashed lines mark the boundaries of the event scored by an expert. For expertsevent, duration, recording conditions
Expert scoring: no respiratory event scored. Severity of sleep apnea in the person recorded: moderate. Amplified by +25 dB so it can be heard, with frequencies below 200 Hz filtered out.
Fading breath
Breathing does not stop completely; the sound gets thinner and weaker, then grows stronger again after a few breaths. This is the hardest one to notice by ear.
Spectrogram: time across, pitch (0 to 5 kHz) upwards. Lighter colour means stronger sound; dashed lines mark the boundaries of the event scored by an expert. For expertsevent, duration, recording conditions
Expert scoring: hypopnea, from second 15 to 32 (16 s). Severity of sleep apnea in the person recorded: moderate. Amplified by +39 dB so it can be heard, with frequencies below 200 Hz filtered out.
Snoring, silence, a deep gasp
The sound of breathing suddenly stops, followed by a silence of more than ten seconds. The silence ends with a loud gasp, as if choking. This is often the "their breathing stops" moment partners describe.
Spectrogram: time across, pitch (0 to 5 kHz) upwards. Lighter colour means stronger sound; dashed lines mark the boundaries of the event scored by an expert. For expertsevent, duration, recording conditions
Expert scoring: obstructive apnea, from second 15 to 31 (16 s). Severity of sleep apnea in the person recorded: severe. Amplified by +30 dB so it can be heard, with frequencies below 200 Hz filtered out.
Repeated pauses
The same cycle several times within a minute: snoring, silence, gasp. If it goes on like this all night, it is a strong reason to see a doctor.
Spectrogram: time across, pitch (0 to 5 kHz) upwards. Lighter colour means stronger sound; dashed lines mark the boundaries of the event scored by an expert. For expertsevent, duration, recording conditions
Expert scoring: obstructive apnea, from second 0 to 10 (10 s); obstructive apnea, from second 22 to 34 (12 s); obstructive apnea, from second 48 to 60 (11 s). Severity of sleep apnea in the person recorded: severe. Amplified by +18 dB so it can be heard, with frequencies below 200 Hz filtered out.
What do experts call an apnea, and what a hypopnea?
An apnea is when airflow stops almost completely (by at least 90%) for at least 10 seconds. A hypopnea is when airflow falls by at least 30% for at least 10 seconds, together with a drop in oxygen or an arousal. In obstructive apnea the chest and belly keep trying to breathe; in central apnea the effort stops too. These rules are applied with a mouth and nose airflow sensor and oxygen measurement, not with sound. Apnea in the glossary · hypopnea
The clips were recorded with a room microphone about 1 m above the bed. The sounds were amplified so they can be heard; quiet breathing was left quieter than the others, as it is in reality. In the spectrograms the colour scale is set to each clip's own level.
Source and licence: The clips come from the PSG-Audio dataset: Korompili G, Amfilochiou A, Kokkalas L et al. PSG-Audio, a scored polysomnography dataset with simultaneous audio recordings for sleep apnea studies. Scientific Data. 2021;8:197. doi:10.1038/s41597-021-00977-w. Licence: CC BY 4.0. The recordings were made at the sleep unit of Sismanoglio Amalia Fleming Hospital in Athens, with local ethics committee approval and the patients' signed consent, and were published without identifying information. Events were scored according to AASM rules, first by a certified technician and then by an experienced sleep physician. We cut the recordings, filtered out frequencies below 200 Hz to reduce room hum, levelled the volume and softened the start and end; we made no other changes. The clips were chosen together with the expert scoring and checked before upload to make sure they contain no speech.