WITH reference to Edwin Funnell’s letter regarding silent telephone calls (Herald, May 31) the most likely explanation is a mis-programmed fax machine or modem.

These devices are often set up to dial a number which may also be used for voice traffic, so will wait for an answering tone.

If they “hear” a voice they will ring off.

This can become a serious problem, particularly where the devices are set to dial in the early hours of the morning to take advantage of off-peak rates.

Another possibility is an “automated dialler” used by a call centre in the hope of keeping recipients hooked on the line until agents are ready to pester them into buying some service that they do not want and never asked for.

Whatever the cause, I recommend that you speak to OfCom for further assistance.

Their website address is: stakeholders.ofcom.org.uk/tell-us/webflow/silent-calls

Andrew Duggan

Marine Place