A dog's bark comes from its ancestor's vocal repertoire. The wolf "bark", not as famous as the wolf "howl", used often by wolves to signal the detection of danger. During my communication research with wolves, I heard the pack bark and bark-howl during the pup season when the pack was on high alert and extremely protective of their new litter. The bark is the most common vocal type of the dog and is produced in many different situational contexts.
Dogs are social creatures like us, so while we talk with one another to communicate, dogs bark to and with each other. It all sounds gibberish to us, but the variability actually means something. One dog's bark can trigger all the dogs on the street (thru social facilitation) and a siren can stimulate a neighborhood chord bark-howl. Barking is perfectly appropriate from the dog's point of view. Unfortunately, when the behavior wakes us up at night or interrupts our work during the day, barking becomes a problem. A noisy nuisance. A cacophony of sounds that can raise the dead and cause strife with neighbors. Though barking may sound like noise when it's disturbing our peace, its acoustic structure carries important information that can help shed light on some attenuating resolutions.
The acoustic variation in a dog's bark can give a listener information about the size, location, behavior, emotional state, and identity of the barker. In fact studies have shown that humans can detect emotional and contextual difference between barks (e.g., Molnár, Kaplan, Roy, Pachet, Pongrácz, Dóka, and Miklósi. Animal Cognition, 2008). Surprisingly, there is little research of how dogs interpret the barks of their conspecifics (e.g., Maros Pongra ́cz, Ba ́rdos, Molna ́r, Farago, and Miklo, Applied Animal Behavior Science, 2008). The bark is a noisy vocal type with a broad range of frequencies. A bark can be heard alone, in a series, or in combination with other vocal types (growls, howls, whimpers, and whines). High pitched barks combined with whines, and/or howls signal the dog is in distress, either physically or psychologically. Low pitched barks combined with growls signal and perceive threat. The number of barks in a series and the time between the barks also provides relevant information. For more details see: https://www.psychologytoday.com/us/blog/canine-corner/201103/what-are-dogs-trying-say-when-they-bark
Prolonged or excessive barking is most distressing and occurs when the trigger (the reason for the barking) is ever present. In order to stop the barking, you first need to find out what is causing the dog to bark. The trigger can be external, such as a passerby, delivery truck, or another dog, or the trigger can be internal such as stress, anxiety, boredom, or pain. A dog that is bored, anxious or confined when left alone will likely bark, and bark a lot until someone removes the trigger or the dog passes out from exhaustion. Often people do not know their dog has been barking because they've been away. It is only a note from a neighbor that informs them of their otherwise "silent" problem.
Let's Bark about It -Part 2 will identify the four main reasons for excessive barking and the first line of defense toward resolution.