A survey conducted by Ericsson and Vodafone Germany found even a one second delay when downloading or uploading content produces a significant negative impact on user experience, subscriber loyalty and the operator brand.

The study states every stakeholder in the mobile ecosystem, including handset manufacturers and content providers, saw a drop in brand engagement as a direct result of a negative network experience.

Millennials in particular are impatient about delays: 72 per cent of German millennial smartphone users lose interest in watching mobile videos if delays exceed four seconds, and their heart rate rises by 44 per cent if they experience delays of two seconds while uploading a selfie.

On average, German millennials were 35 per cent more stressed with mobile delays than adults aged 35 years and over.

Electroencephalography equipment (which records electrical activity in the brain), eye-tracking gear and pulse meters were used to monitor 150 subscribers who completed tasks such as browsing web pages and streaming videos, while a degradation in the quality of service was simulated.

The benefits of knowing the point at which a user becomes frustrated with mobile delays while using apps on the network, and the associated physiological effects, will help operators understand and meet user expectations, redefine service level key performance indicators and shape how networks will be built, the report said.

Participants experienced a 30 per cent rise in stress after a one second delay, but despite 47 per cent showing a decline in interest, most continued to watch the video.

If videos take longer than one second to load, users experience a negative cognitive reaction as they anticipate more interruptions.

Guido Weissbrich, director network performance at Vodafone Germany, said streaming services “must do everything to avoid lengthy buffering or freezing of content.”

Those who were made to believe they were using 3G services were more tolerant and showed less stress towards delays as opposed to 4G users, which implies people who are accustomed to 4G speeds have less tolerance towards video loading delays.

Buffering was found to be more stressful and cause more negative emotions when the video stream was of high resolution.

In fact, users would prefer to watch a fast-loading, lower quality, video rather than a slow loading or interrupted HD one.

The average Net Promoter Score for all German operators fell from a high positive score of +31 to -15 with one second of delay in loading videos on YouTube.

“The responsibility of providing a positive experience rests on all those involved, and future-proof network solutions will need to be worked on collaboratively in order to meet evolving consumer expectations and prevent churn,” the report said.

The results of the study mirrored the trends of past research from the Ericsson ConsumerLab study in February 2016.