The King’s voice has the “potential” to offer the public the same source of stability and comfort as that provided by his mother and grandfather, vocal experts have said.

Both the voice of the Queen and that of her father George VI became a pillar of familiarity, consistency and reassurance to the British people during their lifetime.

Charles, who is set to deliver a televised address to the nation from Buckingham Palace on Friday evening, already has a recognisable voice to the British public.

But vocal experts say he may need to adjust his articulation and annunciation to become “more relatable” as the public adapt to a new monarch’s voice.

Jane Boston, voice practitioner at the Royal School of Speech and Drama, said: “The voice of HRH Elizabeth II has been a constant presence and secure reference point for UK public continuity over the 70-plus years she has been in public life.

“Obviously her accent has changed with the times and with her age but as a social presence it has been a constant.”

Ms Boston said that while the public know Charles’s voice, they are less used to hearing his speech as a “constant source of stability and reassurance”.

She added: “I feel it is something he has the potential to offer but obviously it will take some adjustment for the public ear.

“It is the kind of adjustment anyone needs to make when they have lost a close familial figure in their lives.”

Sonia Beldom, a communications coach and neuro-linguistics programming therapist, said the Queen’s voice was “very, very high” but deepened over the decades.

“In the earlier days she was very much one of them, not one of us,” she explained.

But she said that as the Queen spoke more and more in the lower part of her mouth, it took on a different quality which was “regal but relatable”.

Ms Beldom said: “Everyone would stop and listen to what she had to say and she was very lovely to listen to.”

She said Charles’s voice has also become more relatable over time and is “very reasoned, authoritative and deep” as well as “quite familiar”.

She added: “He has a bit of a drawl and his words can run over each other, rather than the Queen who articulated everything, so he could do with slowing down slightly.”

Ms Beldom also said his speech pattern, pace and tone can be “very predictable”, leading people to “focus on the pattern rather than what’s being said”, so he could vary his speech to become “more accessible”.

She added: “It’s not that he is inaccessible at all but it is just showing a difference in personality.”

Charles also speaks at the back of his throat, unlike his mother who spoke at the front of her mouth which yields “clearer and crisper” speech, Ms Beldom said.

So Charles could work a bit on annunciation and articulation by speaking at the front of his mouth, she said.

Cathryn Robson, voice coach and vocal pedagogy lecturer at the Royal School of Speech and Drama, added: “King Charles III has a voice that is familiar but with different associations.

“It will be interesting to hear if his rather gentle, aspirate and sotto voice tone will change as he grows into the role of King.”