AS YOU PROBABLY KNOW, your dog’s voice is not like a Bret Michaels concert, pumping out a shower of meaningless noise. Although your dog’s vocalizations might be unwelcome at times, those sounds carry way more information and meaning than any of the former frontman’s power ballads can ever hope to do. Well, maybe not as much as “Every Rose Has Its Thorn.” 
In recent years, many studies have investigated the noises made by companion dogs. Now, you (yes, YOU!) can help researchers in a new study  where participants listen to and rate different vocalizations. But first, what have we learned about dog vocalizations so far?
Time to Be All Ears
One major finding: dogs bark differently in different contexts, and it’s possible to tell the difference. Sophia Yin , DVM, MS, found that “disturbance barks” (e.g., barks in response to a stranger ringing the doorbell) sound different from “isolation barks” (when a dog is separated from an owner) as well as barks emitted during play. In each context, barks have specific acoustic parameters: where disturbance barks are “relatively low-pitched, harsh barks with little variation in pitch or loudness,” isolation barks are “higher pitched, more tonal and more frequency-modulated than the disturbance barks,” and play barks are “similar to the isolation barks except that they usually occurred in clusters rather than singly” (Yin, 2010 Blog Post ). Instead of seeing barks as meaningless noise, pay attention. Banjo might be yipping because he’s alone, or he may have noticed that someone uninvited is climbing in through your second floor window.
Dog barks are full of information, but what about growls? Anna Taylor  and colleagues at the University of Sussex studied growling and found that, unlike barks, many acoustic properties of growls recorded in a play and aggressive context did not differ. But aggressive growls were longer than play growls, and play growls had a shorter pause between growls.
While growls are thought to be associated with aggression, remember they can also appear during play, so consider growling in a larger context. Additionally, if you come across a situation where growling could be associated with aggression, don’t freak out. Jolanta Benal , CPDT-KA, CBCC-KA and author of The Dog Trainer on Quick and Dirty Tips, reminds : if you punish a dog for growling, you are essentially punishing a dog for giving a warning. Growling is a form of communication related to emotional or inner states in a particular context. If you want to decrease growling, think about what’s prompting the growling. The growling itself is not a problem.
Many high-profile dog vocalization studies were developed by Péter Pongrácz, Csaba Molnár and Tamás Faragó of the Family Dog Project  at Eötvös Loránd University in Budapest. In one notable study, dogs were placed in a room with a bone, and researchers played a recording of one of three growls from a different dog. Dogs responded to the “this is my food” growl by backing away from the bone, and dogs for the most part ignored the “go away stranger” and the play growl because those growls were not relevant to the bone. All growls are not the same, and dogs know it. So let’s try to get on the same page as them.
While we are learning about the noises coming from dogs’ mouths, we still have a way to go. I recently spoke with Monique Udell , an Assistant Professor at Oregon State University and a canine researcher, for an article on dog vocalizations for The Bark  magazine (view article here ). As Udell pointed out, “Vocal behavior in other species has received a lot of detailed attention. In birds, we’ve looked down to the note sequence and explored tiny variations. Vocalizations are such a prominent feature of dogs, and there is a lot to learn.”
Listen! You Can Help!
Now, back to what YOU can do to advance the science of vocalizations from the comfort of your couch. Tamás Faragó , now a postdoctoral researcher with the MTA-ELTE Comparative Ethology Research Group in Budapest, is exploring how humans perceive emotions in vocalizations. The study asks human subjects (like you!) to listen to and rate different vocalizations on a chart based on how aroused you think the vocalization is and whether you think it’s positive or negative. I promise you will not hear a single note of “Every Rose Has Its Thorn.” Okay, only if you want to . The whole survey takes about a half hour, and as you go along, you’ll you get the swing of it. Check out the details below to participate.
You Can Participate in a Study of the Emotional Content of Sounds
Participants: Anybody in any country
Time commitment: Approximately 30 minutes
Project type: Listen to and rate different sounds
Project needs: Computer with headphones or decent quality speakers
Survey website: http://www.inflab.bme.hu/~viktor/soundrating/index.html 
So don’t just stand there. Listen!
Hecht, J. Dog Speak: The Sounds of Dogs . The Bark Magazine.
Nova. The Meaning of Dog Barks .
Yin, S. Barking Dogs: Noise or Communication?  Dr. Yin’s Animal Behavior and Medicine Blog. Monday, November 15th, 2010.
Taylor et al. 2009. Context-related variation in the vocal growling behaviour of the domestic dog (Canis familiaris).  Ethology, 115, 905–915.
Faragó et al. 2010. ‘The bone is mine’: affective and referential aspects of dog growls.  Animal Behaviour, 79, 917–925.
Yin and McCowan. 2004. Barking in domestic dogs: context specificity and individual identification . Animal Behaviour, 68, 343–355.
About the Author
Julie Hecht, MSc, is a canine behavioral researcher and science writer in New York City. She writes a behavior column for The Bark. She would really like to meet your dog. Follow on Dog Spies at Facebook  and Twitter @DogSpies  | DogSpies.com 
This story was originally published by Scientific American.  Reprinted with permission.