Mumbling is just a way of describing unclear speech, or speech that cannot be easily heard or understood. It’s annoying if you are the listener, because it requires extra effort to translate the bits of information you can glean from what you hear into something wholly intelligible. It’s also annoying for the speaker, who is often asked to repeat what they have just said.
While it may be a mild annoyance in a social situation, it can be quite damaging in a professional situation. People who speak clearly and audibly are much more likely to get the job than those who don’t get their message across first time.
There are many, complex underlying causes for mumbling. In physical terms, the muscles involved in articulating, or shaping the speech sounds are simply not activated adequately. This could be because the speaker is tired, or holding back because of shyness, or insecurity about the situation.
Let’s look at the last one: insecurity. If you are not comfortable that you know what you are talking about, either because you haven’t done your homework, or because you don’t have faith that you have the right to be talking on this topic, it may well be that you are unconsciously restricting the muscular effort in an attempt (misguided!) to protect yourself from criticism.
Whatever the underlying reason, speaking is a physical act, involving muscles, and if the muscles are not positioning themselves accurately or powerfully enough, the speech will be unclear.
Now, let’s be very clear about which speech sounds we are talking about. The most popular remedy for mumbling is to do lots of tongue twisters. These are phrases involving complicated sequences of consonants, that require a relaxed jaw, an agile tongue and accurate placement. For example,
Peter Piper picked a peck of pickled peppers
Thirty thick thistle sticks
She sells sea shells by the sea shore.
In my opinion, heading straight to the tongue twisters is putting the cart before the horse. You Doing them does not address the underlying problem, which is a tense, immobile jaw and a tight, inflexible tongue. First you have to learn how to relax the jaw, creating more space in the mouth and providing more room for the tongue to be more flexible, and agile. A relaxed jaw also means relaxed facial , mouth and throat muscles, including the lips and the soft palate, so that they will be in a better position to allow for more accurate placement of the combinations of lips, tongue, teeth, jaw and palates.
So if you have a problem with mumbling, start working on relaxing your jaw. That means actually letting it go, letting it drop down until you can slip 2 fingertips between your teeth without straining. This takes time.
Be kind to your jaw. It’s been working hard all your life to keep you safe behind its guardrail. Give it a break. Send it to the Bahamas for a rest. It will thank you for it, eventually.
I’ll pop some jaw relaxation exercises online in a day or two, on the Products page.