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These data are from the study by Howell, Davis, Bartrip, and Wormald (2004). The study looked at the fluency-enhancing effects of speaking at the same time as a frequency shifted version of the voice. There were 14 speakers and four recording per speaker making 56 files in all. Recording are in SFS format (see Howell & Huckvale, 2004 for a description). The four recordings for a speaker were for two texts (Alice and Kate, see below) and two readings of each text. Filenames start with a four figure code that identifies the speaker (e.g. 0075), followed by underscore, recording number (r1-r4), underscore text (1=Alice, 2=Kate), underscore and four letters representing feedback sequence on the 50-word sections (n=normal listening, f=FSF). The texts alternate between easy and difficult linguistic material as specified in Howell et al. (2004).  Easy and difficult sections are marked in the texts.

Texts used in the experiment


The following conversation is between Alice and her teacher, Mrs Jones. They are talking about what they did at Easter.

(Easy) I went to the fair. And then I played with my friend. We got some candy floss and some toffee apples. They were nice and sweet. And then we went on the ferris wheel for ages. It was so fun. It was the best fair I have ever been to.

 (Difficult) That sounds particularly enjoyable Alice. I’m sure you had a wonderful time especially as it was your birthday. Were you given many exciting presents by your family and friends? Did any other unusual or surprising things happen or do you remember anything else that you want to tell me about?

Alice wrinkled her forehead as she tried to remember the best parts of her birthday. Then she nodded, and said:

 (Easy) Yes. I got lots of great presents. My mum gave me a hamster. He is so cute and soft. I called him Andy. I also got a ball that he can run around the house in. He looks funny when he does that. And my dad gave me a kite.

(Difficult) That’s terrific. I adored my pet hamster when I was about thirteen. My favourite game was to hide hundreds of tiny pieces of his food all around my bedroom and then allow him to scurry about and discover where they all were before he gobbled them all up incredibly quickly.

They both laughed. It seemed they had lots in common, even though Mrs Jones was a teacher and Alice wasn’t.


Kate witnessed the robbery of a woman’s handbag. The police were called and had arrived to ask her some questions.

(Difficult) Mrs Mcalpine please could you give us a clear and accurate description of the thief including any unusual distinguishing characteristics. Please be careful not to omit any critical details as these are probably the most important features that will help us to track down and arrest and hopefully prosecute him.

(Easy) Of course. he was a young man. probably aged between fifteen and twenty. He was wearing a blue tracksuit. He had brown hair and was wearing a cap. The cap was also blue. He was about six foot tall and he was wearing yellow trainers with blue stripes on them.

The policeman carefully wrote down the information Katie had given him and then looked up to ask her another question.

(Difficult) Could you describe exactly what you witnessed. Again be extremely careful to mention every single detail however small. We need detailed information about exactly what happened so that we can determine what to do next. Your witness account is very important to our investigation so be as accurate as possible.

(Easy) I had just bought a cup of tea. An old lady was in the queue behind me. She ordered a drink. I went to sit down. The lady opened her bag to get her purse. All of a sudden the young man behind her snatched her bag and ran off.

Kate answered more questions before the police moved on to the next witness. She hoped they would catch the thief.


Howell, P., Davis, S., Bartrip, J. & Wormald, L. (2004). Effectiveness of frequency shifted feedback at reducing disfluency for linguistically easy, and difficult, sections of speech (original audio recordings included). Stammering Research, 1, 309-315.

Howell, P., & Huckvale, M. (2004). Facilities to assist people to research into stammered speech. Stammering Research, 1, 130-242.

Dysfluent Frequency Shifted Feedback (Reading)

( August 2004)

Audio-Only in SFS format

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